#include <fstream>
using namespace std;

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

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

int main(){
    int a,b;
    long long int x,y;
    fin>>a>>b;
    int gcd = gcdExt(a,b,x,y);
    if(x <= 0) x = b*x%b;
    fout<<x;
}