代碼如下:
#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;
long long exgcd(long long a,long long b,long long &x,long long &y)
{
if(b==0)
{
x=1;
y=0;
return a;
}
else
{
long long ans=exgcd(b,a%b,x,y);
long long t=y;
y=x-(a/b)*y;
x=t;
return ans;
}
}
int main()
{
long long X,Y,m,n,L,x,y;
scanf("%lld %lld %lld %lld %lld",&X,&Y,&m,&n,&L);
long long a=m-n,b=L,c=Y-X;//此處該是正數就是正數,該是負數就是負數。
long long g=exgcd(a,b,x,y);
if(c%g) cout << "Impossible" << endl;
else
{
c/=g;
b/=g;
x=x*c%b;
x=(x+abs(b))%abs(b);
cout << x << endl;
}
return 0;
}