北大OJ1061

#include<iostream>
using namespace std;
long long extend_gcd(long long a,long long b,long long &x,long long &y)
{
	long long t,m;
	if((b==0)&&(a==0))return -1;
	if(b==0)
	{
		x=1;y=0;return a;
	}
	else
	{
		m=extend_gcd(b,a%b,x,y);
	    t=x;x=y;y=t-(a/b)*y;
	}
	return m;
}
int main()
{
	long long x,y,m,n,L,X,Y,d,r;
	while(cin>>x>>y>>m>>n>>L)
	{
		d=extend_gcd(n-m,L,X,Y);r=L/d;
		if((x-y)%d)cout<<"Impossible"<<endl;
		else cout<<((x-y)/d*X%r+r)%r<<endl;
	}
	return 0;
}