#include <cstdio>
using namespace std;

long long a,n;

//verifica ecuatia a * x + b * y = d    unde d este cmmdc(a,b)
void euclidextins(long long a, long long b, long long &d, long long &x, long long &y)
{
    if (b == 0)
    {
        x = 1;
        y = 0;
        d = a;
    }
    else
    {
        long long x0, y0;
        euclidextins(b,a % b,d,x0,y0);
        x = y0;
        y = x0 - (a / b) * y0;
    }
}

void citire()
{
    freopen("inversmodular.in","r",stdin);
    freopen("inversmodular.out","w",stdout);
    scanf("%lld%lld",&a,&n);
}

int main()
{
    long long d,x,y;
    citire();
    euclidextins(a,n,d,x,y);
    while (x < 0)
        x += n;
    printf("%lld\n",x);
    return 0;
}