#include <bits/stdc++.h>

using namespace std;
#define ll long long

ifstream fin("inversmodular.in");
ofstream fout("inversmodular.out");

ll a,n,y,inv;

void gcd(ll &x,ll &y,ll a, ll b)
{
    if(b==0)
        x=1,y=0;
    else
    {
        gcd(x,y,b,a%b);
        ll aux=x;
        x=y;
        y=aux-y*(a/b);
    }
}
int main()
{
    fin>>a>>n;
    ll inv;
    gcd(inv,y,a,n);
    if(inv<=0)
        inv+=n;
    fout<<inv;
    return 0;
}