#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <cstdio>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <cctype>
using namespace std;
long long n;
bool solve(long long x, long long y, long long z) {
	long long co = 0;
	long long now = 1;
	for (long long i = 0; i < z; i++) {
		co += now * y;
		if (1000000000000000000 / now < x && i != z - 1) {
			return true;
		}
		now *= x;
	}
	if (co >= n) {
		return true;
	}
	else {
		return false;
	}
}
int main() {
	cin >> n;
	long long ans = 1000000000000007;
	for (long long i = 1; i * i <= n; i++) {
		if (n % i == 0) {
			for (long long j = 1; j < 42; j++) {
				long long l = i, r = 1000000000000000;
				while (r - l > 1) {
					long long mid = (l + r) / 2;
					if (solve(mid, i, j)) {
						r = mid;
					}
					else {
						l = mid;
					}
				}
				bool a = true;
				long long co = 0;
				long long now = 1;
				for (long long k = 0; k < j; k++) {
					co += now * i;
					if (1000000000000000000 / (now*i) < r && k != j - 1) {
						a = false;
						break;
					}
					now *= r;
				}
				if (co != n) {
					a = false;
				}
				if (a) {
					if (ans > r) {
						ans = r;
					}
				}
			}
		}
		if (n % i == 0) {
			for (long long j = 1; j < 42; j++) {
				long long l = n / i, r = 1000000000000000 / j;
				while (r - l > 1) {
					long long mid = (l + r) / 2;
					if (solve(mid, n / i, j)) {
						r = mid;
					}
					else {
						l = mid;
					}
				}
				bool a = true;
				long long co = 0;
				long long now = 1;
				for (long long k = 0; k < j; k++) {
					co += now * (n / i);
					if (100000000000000000 / (now * (n / i)) < r && k != j - 1) {
						a = false;
						break;
					}
					now *= r;
				}
				if (co != n) {
					a = false;
				}
				if (a) {
					if (ans > r) {
						ans = r;
					}
				}
			}
		}
	}
	cout << ans << endl;
}