#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005

int main() {
    ll n;
    cin >> n;
    ll ans = 1001001;
    srep(i,2,100){
        srep(j,1,100){
            if(i*j>=ans)continue;
            ll x = 1;
            rep(k,j) x *= (ll)i;
            if(x >= n) ans = i*j;
        }
    }
    cout << ans << endl;
    return 0;
}