poj 1061

#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;
typedef long long ll;
ll extgcd(ll a,ll b,ll &x,ll &y)
{
    ll d=a;
    if(b!=0)
    {
        d=extgcd(b,a%b,y,x);
        y-=(a/b)*x;
    }
    else
    {
        x=1;y=0;
    }
    return d;
}
ll realgcd;
int main()
{
    ll x,y,m,n,l,e,k;
    while(cin>>x>>y>>m>>n>>l){
    realgcd=extgcd(n-m,l,e,k);
    ll r=l/realgcd;
    ll tmp=x-y;
    if(tmp%realgcd!=0)
    {
        cout<<"Impossible"<<endl;
    }
    else
    {
        cout<<((x-y)/realgcd*e%r+r)%r<<endl;
    }
}}