#include <fstream>

using namespace std;
ifstream cin("inversmodular.in");
ofstream cout("inversmodular.out");
void euclid(int a, int b, int &x, int &y)
{
    if(b>0)
    {
        euclid(b,a%b,x,y);
        int x1=x,y1=y;
        y=x1-(a/b)*y1;
        x=y1;
    }
    else
    {
        x=1;
        y=0;
    }
}
int main()
{
    int n,a,x,y;
    cin>>a>>n;
    euclid(a,n,x,y);
    if(x<0)
        cout<<n+x%n;
    else
        cout<<x%n;
    return 0;
}