#include <bits/stdc++.h>   using namespace std;   int main() {     long long m, s = -1, l = 1, r = 1e18;     cin >> m;     while (l <= r) {       long long as = 0, i;       long long mid = (l + r) / 2;       for (i = 2; i * i * i <= mid; i++) as += mid / (i * i * i);       if (as == m) s = mid;       if (as >= m)         r = mid - 1;       else         l = mid + 1;     }     cout << s;   }   