#include <cstdio>

using namespace std;

typedef long long ll;

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

int main()
{
    freopen("inversmodular.in", "r", stdin);
    freopen("inversmodular.out", "w", stdout);
    int a,n;
    scanf("%d%d",&a,&n);
    ll x,y;
    euclid(a,n,x,y);
    x=(x%n+n)%n;
    printf("%d",x);
    return 0;
}