算法3

import java.util.Scanner;

public class New3 {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		New3frog A = new New3frog();
		New3frog B = new New3frog();
		A.setIndex(scan.nextInt());
		B.setIndex(scan.nextInt());
		A.setSpeed(scan.nextInt());
		B.setSpeed(scan.nextInt());		
		int L = scan.nextInt();
		int x = A.getIndex();
		int m = A.getSpeed();
		int y = B.getIndex();
		int n = B.getSpeed();

		int diffIn;
		int diffSe;
		if(x>y){
			diffIn = x-y;
		}else{
			diffIn = y-x;
		}
		if(m>n){
			diffSe = m-n;
		}else{
			diffSe = n-m;
		}
		if(diffIn == 0){
			if(diffSe == 0){
				System.out.println("0");
			}else{
				for(int i = 1; ; i++){
					if((diffSe*i+diffIn)%L == 0){
						System.out.println(i);
						break;
					}
				}				
			}
		}else{
			if(diffSe == 0){
				System.out.println("impossible!");
			}else{
				if((x-y)*(m-n)>0){
					for(int i = 1; ; i++){
						if((diffSe*i+diffIn)%L == 0){
							System.out.println(i);
							break;
						}
					}				
				}else{
					for(int i = 1; ; i++){
						if((diffSe*i%L == (diffIn))){
							System.out.println(i);
							break;
						}
					}	
				}
				
			}
		}	
	}

}





public class New3frog {
	private int index;
	private int speed;
	
	public int getIndex() {
		return index;
	}
	public void setIndex(int index) {
		this.index = index;
	}
	public int getSpeed() {
		return speed;
	}
	public void setSpeed(int speed) {
		this.speed = speed;
	}
	
}