#include<cstdio>

using namespace std;

int x,n,a,b;

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

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