#include <fstream>
using namespace std;
void euclid(long long a, long long b, long long &x, long long &y, long long &d)
{
    if (b == 0)
    {
        d = a;
        x = 1;
        y = 0;
        return;
    }
    long long xx, yy, q = a / b;
    euclid(b, a % b, xx, yy, d);
    x = yy;
    y = xx - yy * q;
}
int main()
{
    ifstream cin("inversmodular.in");
    ofstream cout("inversmodular.out");
    long long a,n,x,y,d;
    cin>>a>>n;
    euclid(a,n,x,y,d);
    cout<<(n+x%n)%n;
    return 0;
}