#include <iostream>
#include <fstream>
using namespace std;
ifstream in("inversmodular.in");
ofstream out("inversmodular.out");
long long A,N,x,y,d;
void EuclidE(long long a,long long b,long long &x,long long &y, long long &d){
    if(b==0){
        x=1;
        d=a;
    }
    else{
        long long x0,y0;
        EuclidE(b,a%b,x0,y0,d);
        x=y0;
        y=x0-a/b*y0;
    }
}
int main()
{
    in>>N>>A;
    EuclidE(N,A,x,y,d);
    while(y<0){y+=N;}
    out<<y;

    return 0;
}