#include<stdio.h>
#include<math.h>
void main()
{
	int i;
	long x,y,m,n,l;
	long v,xyl,sum,temp;
	scanf("%d%d%d%d%d",&x,&y,&m,&n,&l);
	if(x==y) printf("0\n");
	else if(x!=y&&m==n) printf("Impossible\n");
	else
	{
		if(m>n) 
		{
			v=m-n;
			temp=x;
			x=y;
			y=temp;
		}       //y×·x,x&Iuml;à&para;&Ocirc;&frac34;&sup2;&Ouml;&sup1;
		else v=n-m;
		sum=y;
		i=0;
		while(1)
		{
			sum+=v;
			i++;
			if(sum%l==x)
			{
				printf("%d\n",i);
				break;
			}
			else if(sum%l==y)
			{
				printf("Impossible\n");
				break;
			}
		}
	}
}