#minhnhat1110

#include <bits/stdc++.h>
#define ll long long
using namespace std;
ll giaithua(ll n)
{
    ll res = 1;
    for (int i = 1; i <= n; i++) {
        res *= i;
    }
    return res;
}

int main()
{
    freopen("TIMSO.inp","r",stdin);
    freopen("TIMSO.out","w",stdout);
    ll N;
    cin >> N;
    ll k = giaithua(N);
    ll d = N;
    while (true) {
        ll p = d * k;
        ll cp = static_cast<ll>(sqrt(p));

        if (cp * cp == p) {
            break;
        }
        d++;
    }

    cout << d ;
    return 0;
}