#include <iostream>
#include <fstream>

using namespace std;

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

int kt[100];

void euclid(int &a, int b, int &k)
{
    while(b)
    {
        int r;
        r = a % b;
        kt[++k]=a/b;
        a = b;
        b = r;
    }
}

void solutii(int &a, int &b, int k)
{
    int i, x = 1, y = 0;
    a=x;b=y;
    for(i=k; i>=1; i--)
    {
        a = y;
        b = x - y * kt[i];
        x = a;
        y = b;
    }
}

int main()
{
    int a, b, k;

    fin >> a >> b;

    k = 0;
    euclid(a, b, k);
    int x=0, y=0, d;
    d = 1 / a;
    solutii(x, y, k);

    while(x<0)
            x=x+b;
    fout<<x%b;



    return 0;
}