#include<iostream>
using namespace std;
int main(){
int m;
int n;
int L;
int x;
int y;
int t=1;
int i=1;
  while(cin>>x>>y>>m>>n>>L){}
  if(m==n){cout<<"Impossible"<<endl;}
    else {
               while((x+m*t)%L!=(y+n*t)%L){
                                  i++;t++;}
         }
        cout<<i<<endl;
          return 0;
}