#include <fstream>
using namespace std;

void euclid(int a,int b,int& x,int& y){
    if(b == 0){
        x = 1;
        y = 0;
        return;
    }
    else{
        int x0,y0;
        euclid(b,a%b,x0,y0);
        x = y0;
        y = x0 - (a/b) * y0;
        return;
    }
}

int main()
{
    ifstream fin("inversmodular.in");
    ofstream fout("inversmodular.out");

    int A,B;
    fin >> A >> B;
    int x,y;
    euclid(A,B,x,y);
    while(x < 0) x += B;
    fout << x;
}