#include <cstdio>

using namespace std;

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

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