diff --git a/src/Acceleration.java b/src/Acceleration.java
index e44caaa..37babc8 100644
--- a/src/Acceleration.java
+++ b/src/Acceleration.java
@@ -1,23 +1,21 @@
-import java.util.*;
-
 public class Acceleration {
 	private double mass;
-	private Vector2 force;
+	private Pair<Double> force;
 	private Velocity velocity;
 	private Onground onground;
-	private Vector2 acceleration;
+	private Pair<Double> acceleration;
 
 	public void updateMass(double mass) {
 		this.mass = mass;
-		acceleration = (this.onground.getOnground() ? new AbstractMap.SimpleEntry<>((force.getKey() / mass), 0.0)
-				: new Vector2((force.getX() / mass), (force.getY() / mass)));
+		acceleration = (this.onground.getOnground() ? new Pair<>((force.getX() / mass), 0.0)
+				: new Pair<>((force.getX() / mass), (force.getY() / mass)));
 		velocity.updateAcceleration(acceleration);
 	}
 
-	public void updateForce(Vector2 force) {
+	public void updateForce(Pair<Double> force) {
 		this.force = force;
-		acceleration = (this.onground.getOnground() ? new Vector2((force.getX() / mass), 0.0)
-				: new Vector2((force.getX() / mass), (force.getY() / mass)));
+		acceleration = (this.onground.getOnground() ? new Pair<>((force.getX() / mass), 0.0)
+				: new Pair<>((force.getX() / mass), (force.getY() / mass)));
 		velocity.updateAcceleration(acceleration);
 	}
 
@@ -26,7 +24,7 @@
 		this.onground = onground;
 	}
 
-	public Vector2 getAcceleration() {
+	public Pair<Double> getAcceleration() {
 		return acceleration;
 	}
 }
\ No newline at end of file
diff --git a/src/Force.java b/src/Force.java
index ea94daa..a2aa9b3 100644
--- a/src/Force.java
+++ b/src/Force.java
@@ -1,8 +1,6 @@
-import java.util.*;
-
 public class Force {
 	private Acceleration acceleration;
-	private Vector2 force;
+	private Pair<Double> force;
 
 	public Force(Acceleration acceleration) {
 		this.acceleration = acceleration;
@@ -13,7 +11,7 @@
 		acceleration.updateForce(force);
 	}
 
-	public Vector2 getForce() {
+	public Pair<Double> getForce() {
 		return force;
 	}
 }
\ No newline at end of file
diff --git a/src/JumpGame.java b/src/JumpGame.java
index 33afe0a..70f05c7 100644
--- a/src/JumpGame.java
+++ b/src/JumpGame.java
@@ -1,5 +1,3 @@
-import java.util.*;
-
 public class JumpGame {
 	private Time time = new Time();
 	private Position position = new Position();
@@ -30,11 +28,11 @@
 		this.mass.setMass(x);
 	}
 
-	public Vector2 getAcceleration() {
+	public Pair<Double> getAcceleration() {
 		return acceleration.getAcceleration();
 	}
 
-	public Map.Entry<Double, Double> getMove() {
+	public Pair<Double> getMove() {
 		return move.getMove();
 	}
 
@@ -50,15 +48,15 @@
 		return ground.getGround();
 	}
 
-	public Vector2 getForce() {
+	public Pair<Double> getForce() {
 		return force.getForce();
 	}
 
-	public Vector2 getVelocity() {
+	public Pair<Double> getVelocity() {
 		return velocity.getVelocity();
 	}
 
-	public Vector2 getPosition() {
+	public Pair<Double> getPosition() {
 		return position.getPosition();
 	}
 
diff --git a/src/Move.java b/src/Move.java
index 2c56556..cbbcbc6 100644
--- a/src/Move.java
+++ b/src/Move.java
@@ -1,8 +1,6 @@
-import java.util.*;
-
 public class Move {
 	private Velocity velocity;
-	private Vector2 move;
+	private Pair<Double> move;
 
 	public Move(Velocity velocity) {
 		this.velocity = velocity;
@@ -17,7 +15,7 @@
 		this.move.setX(x);
 	}
 
-	public Vector2 getMove() {
+	public Pair<Double> getMove() {
 		return move;
 	}
 }
\ No newline at end of file
diff --git a/src/Pair.java b/src/Pair.java
new file mode 100644
index 0000000..95f6959
--- /dev/null
+++ b/src/Pair.java
@@ -0,0 +1,26 @@
+// 2 dim
+public class Pair<Type> {
+	private Type x;
+	private Type y;
+
+	public Pair(Type x, Type y) {
+		this.x = x;
+		this.y = y;
+	}
+
+	public void setX(Type x) {
+		this.x = x;
+	}
+
+	public void setY(Type y) {
+		this.y = y;
+	}
+
+	public Type getX() {
+		return (this.x);
+	}
+
+	public Type getY() {
+		return (this.y);
+	}
+}
diff --git a/src/Position.java b/src/Position.java
index a7652e0..f185b73 100644
--- a/src/Position.java
+++ b/src/Position.java
@@ -1,27 +1,25 @@
-import java.util.*;
-
 public class Position {
-	private Vector2 velocity;
+	private Pair<Double> velocity;
 	private boolean ground;
-	private Vector2 position;
+	private Pair<Double> position;
 
-	public void updateVelocity(Vector2 velocity) {
+	public void updateVelocity(Pair<Double> velocity) {
 		this.velocity = velocity;
 		position = (((ground == true) && ((this.position.getY() + (0.01 * velocity.getY())) < 0.0))
-				? new Vector2(this.position.getX() + (0.01 * velocity.getX()), 0.0)
-				: new Vector2(this.position.getX() + (0.01 * velocity.getX()),
+				? new Pair<>(this.position.getX() + (0.01 * velocity.getX()), 0.0)
+				: new Pair<>(this.position.getX() + (0.01 * velocity.getX()),
 						(this.position.getY() + (0.01 * velocity.getY()))));
 	}
 
 	public void updateGround(boolean ground) {
 		this.ground = ground;
 		position = (((ground == true) && ((this.position.getY() + (0.01 * velocity.getY())) < 0.0))
-				? new Vector2(this.position.getX() + (0.01 * velocity.getX()), 0.0)
-				: new Vector2(this.position.getX() + (0.01 * velocity.getX()),
+				? new Pair<>(this.position.getX() + (0.01 * velocity.getX()), 0.0)
+				: new Pair<>(this.position.getX() + (0.01 * velocity.getX()),
 						this.position.getY() + (0.01 * velocity.getY())));
 	}
 
-	public Vector2 getPosition() {
+	public Pair<Double> getPosition() {
 		return position;
 	}
 }
\ No newline at end of file
diff --git a/src/Vector2.java b/src/Vector2.java
deleted file mode 100644
index 3763446..0000000
--- a/src/Vector2.java
+++ /dev/null
@@ -1,28 +0,0 @@
-import java.util.*;
-
-// 2 dim
-public class Vector2 {
-	private double x;
-	private double y;
-
-	public Vector2(double x, double y) {
-		this.x = x;
-		this.y = y;
-	}
-
-	public void setX(double x) {
-		this.x = x;
-	}
-
-	public void setY(double y) {
-		this.y = y;
-	}
-
-	public double getX() {
-		return (this.x);
-	}
-
-	public double getY() {
-		return (this.y);
-	}
-}
diff --git a/src/Velocity.java b/src/Velocity.java
index 204d67c..28f5d90 100644
--- a/src/Velocity.java
+++ b/src/Velocity.java
@@ -1,22 +1,20 @@
-import java.util.*;
-
 public class Velocity {
-	private Vector2 acceleration;
-	private Vector2 move;
+	private Pair<Double> acceleration;
+	private Pair<Double> move;
 	private Position position;
 	private Onground onground;
-	private Vector2 velocity;
+	private Pair<Double> velocity;
 
-	public void updateAcceleration(Vector2 acceleration) {
+	public void updateAcceleration(Pair<Double> acceleration) {
 		this.acceleration = acceleration;
 		velocity = ((this.onground.getOnground() && (this.velocity.getY() < 0.0))
-				? new Vector2(this.velocity.getX() + (0.01 * acceleration.getX()), 0.0)
-				: new Vector2(this.velocity.getX() + (0.01 * acceleration.getX()),
+				? new Pair<>(this.velocity.getX() + (0.01 * acceleration.getX()), 0.0)
+				: new Pair<>(this.velocity.getX() + (0.01 * acceleration.getX()),
 						(this.velocity.getY() + (0.01 * acceleration.getY()))));
 		position.updateVelocity(velocity);
 	}
 
-	public void updateMove(Vector2 move) {
+	public void updateMove(Pair<Double> move) {
 		this.move = move;
 		velocity = ((this.onground.getOnground() && (move.getY() >= 0.0)) ? move : this.velocity);
 		position.updateVelocity(velocity);
@@ -27,7 +25,7 @@
 		this.onground = onground;
 	}
 
-	public Vector2 getVelocity() {
+	public Pair<Double> getVelocity() {
 		return velocity;
 	}
 }
\ No newline at end of file