#include<bits/stdc++.h>
using namespace std;

ifstream f("inversmodular.in");
ofstream g("inversmodular.out");

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

int main()
{
    int a,b,d,x,y;
    f>>a>>b;
    euclid(a,b,d,x,y);
    while(x<0)
        x+=b;
    g<<x;
    return 0;
}