#include<stdio.h>

int main(){
__int64 x,y,m,n,l,s,r,p,t=1;
scanf("%I64d %I64d %I64d %I64d %I64d",&x,&y,&m,&n,&l);
x=x%l;
y=y%l;
m=m%l;
n=n%l;
s=m-n;
r=(s-y+x)%l;
if(r<0) r+=l;
p=r;
do{
t++;
p+=s;
p=p%l;
if(p<0) p+=l;
}
while(p!=0&&p!=r);
if(p==0) printf("%I64d",t);
else printf("Impossible");
return 0;
}