#include <cstdio>
#define ll long long
using namespace std;

ll a,n;

void Read()
{
    freopen("inversmodular.in","r",stdin);
    scanf("%lld%lld",&a,&n);
}

inline void cmmdc(ll a,ll b,ll &x,ll &y)
{
    if (b==0)
    {
        x=1;
        y=0;
    }
    else
    {
        cmmdc(b,a%b,x,y);
        ll aux=x;
        x=y;
        y=aux-y*(a/b);
    }
}

void Write()
{
    ll inv,y;
    freopen("inversmodular.out","w",stdout);

    cmmdc(a,n,inv,y);
    if (inv<0) inv=inv%n+n;

    printf("%lld",inv);
}

int main()
{
    Read();
    Write();
    return 0;
}