#include <bits/stdc++.h>
#define int long long

using namespace std;

int gcd(int a, int b, int& x, int& y)
{
    if(b==0)
    {
        x=1, y=0;
        return a;
    }
    int x1, y1;
    int d=gcd(b, a%b, x1, y1);
    x=y1;
    y=x1-y1*(a/b);
    return d;
}

signed main()
{
    ifstream cin("inversmodular.in");
    ofstream cout("inversmodular.out");
    int a, m, x, y;
    cin>>a>>m;
    int g=gcd(a, m, x, y);
    x=(x%m+m)%m;
    cout<<x;
    return 0;
}