```c
#include<bits/stdc++.h>
using namespace std;
#define int long long
int exgcd(int a, int b, int &x, int &y){
if(b == 0){
x = 1, y = 0;
return a;
}
int d = exgcd(b, a % b, x, y);
int t = x;
x = y;
y = t - a / b * y;
return d;
}
signed main(){
int x, y, n, m, l;
cin>>x>>y>>n>>m>>l;
int a = m - n, c = x - y, b = l;
if(a < 0) a = -a, c = -c;
//ax + by = c
int xx = 0, yy = 0;
int tt = exgcd(abs(a), abs(b), xx, yy);
if(c % tt) puts("Impossible");
else{
int k = c / tt;
xx *= k;
cout<<((xx % l) + l) % l<<endl;
}
return 0;
}
```
by WRuperD @ 2022-07-12 08:47:33
最后一个判断改成：
```cpp
else cout<<c/tt*xx%(b/tt)+b/tt)%(b/tt);
```
by Yizhixiaoyun @ 2022-07-12 09:00:51