#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cstring>
#include<algorithm>

using namespace std;

const int maxn=1000100;
const int INF=(1<<28);
typedef long long ll;

ll a,b,m,n,L;
ll x,y;

ll exgcd(ll a,ll b,ll &x,ll &y)
{
    if(b==0){
        x=1;y=0;
        return a;
    }
    ll r=exgcd(b,a%b,x,y);
    ll t=y;
    y=x-(a/b)*y;
    x=t;
    return r;
}

bool mod_linear_equation(ll a,ll b,ll n)
{
    ll d=exgcd(a,n,x,y);
    if(b%d) return false;
    x=x*(b/d)%n;
    x=(x+n/d)%(n/d);
    return true;
}

int main()
{
    while(cin>>a>>b>>m>>n>>L){
        if(m-n<0){
            swap(m,n);
            swap(a,b);
        }
        if(mod_linear_equation(m-n,b-a,L)) cout<<x<<endl;
        else cout<<"Impossible"<<endl;
    }
    return 0;
}