#include <fstream>

using namespace std;

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

int cmmdc(int a, int b, int &x, int &y)
{
    if(b==0)
    {
        x=1, y=0;
        return a;
    }
    int d=cmmdc(b, a%b, x, y), aux=x;
    x=y;
    y=aux-a/b*y;
    return d;
}
int invers(int a, int n)
{
    int x, y, d=cmmdc(a, n, x, y);
    while(x<0)
        x+=n;
    return x%n;
}
int main()
{
    int a, n;
    fin>>a>>n;
    fout<<invers(a, n);
    return 0;
}