#include<stdio.h>
#include<iostream>
using namespace std;
int main()
{
	unsigned long x,y,m,n,L;
	scanf("%d%d%d%d%d",&x,&y,&m,&n,&L);
	unsigned long s;
	for(s=1;s<2000000000;s++)
	{
		x=(x+m)%L;
		y=(y+n)%L;
		if(x==y)
		{
			printf("%d\n",s);
			exit(1);
		}
	}
	printf("Impossible\n");
	return 0;
}