#include<stdio.h>
int A,N;

void euclid(int a, int b, int &x, int &y)
{
    //printf("%d %d\n",a,b);
    if(b==0)
    {
        x=1;
        y=0;
        return;
    }

    int x0,y0;
    euclid(b,a%b,x0,y0);
    x = y0;
    y = x0 - a/b * y0;
    return;
}

int main()
{
    freopen("inversmodular.in","r",stdin);
    freopen("inversmodular.out","w",stdout);

    scanf("%d%d",&A,&N);
    int x,y;
    euclid(A,N,x,y);

    if(x<0)
    {
        y = (-x-1)/N + 1;
        x += y*N;
    }
    printf("%d",x%N);
    return 0;
}