#include <bits/stdc++.h>
using namespace std;
using ll = long long;

template<typename T>
T MUL(T a, T b){
    T res;
    return __builtin_mul_overflow(a, b, &res)? std::numeric_limits<T>::max() : res;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll A, ans = 1ll << 60;
    cin >> A;
    for(ll i = 2; i <= 100; i++){
        ll v = i;
        for(int j = 2; j <= 100; j++){
            v = MUL(v, i);
            if(v >= A){
                ans = min(ans, j * i);
                break;
            }
        }
    }
    cout << ans << '\n';
}