#include <iostream>
#include <cstdio>

using namespace std;

void euclid(int a,int b,int &x,int &y)
{
    int x1,y1;
    if(b)
    {
        euclid(b,a%b,x1,y1);
        x=y1;
        y=x1-(a/b)*y1;
    }
    else
    {
        x=1;
        y=0;
    }
}

int main()
{
    int n,m,x,y;
    freopen("inversmodular.in","r",stdin);
    freopen("inversmodular.out","w",stdout);
    cin>>n>>m;
    euclid (n,m,x,y);
    while(x<0)
        x+=n;
    cout<<x;
    return 0;
}