#include <iostream>
#include <fstream>

using namespace std;

long long x,y,a,b;

void gcd(int a, int b)
{
    if(b==0)
        x=1,y=0;
    else
    {
        gcd(b,a%b);
        long long aux=x;
        x=y;
        y=aux- y*(a/b);
    }
}

int main()
{
    ifstream in("inversmodular.in");
    ofstream out("inversmodular.out");
    in >> a >> b;
    gcd(a,b);
    if(x<0)
        x=b+x%b;
    out << x;
    return 0;
}