#include <iostream>
#include <string>
#include <sstream>
#include <stack>
#include <algorithm>
#include <cmath>
#include <queue>
#include <bitset>
#include <iomanip>
#include <limits>
#include <chrono>
#include <random>
#include <array>
#include <unordered_map>
#include <functional>
#include <complex>
#include <numeric>
#include <cctype>
#include <map>
#include <set>
#include <cstdlib>
#include <bitset>
#include <tuple>
#include <assert.h>
#include <deque>
#include <utility>
#include <fstream>

using namespace std;
typedef long long ll;
using ull = unsigned long long;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
//template<typename T> T gcd(T a, T b) { a = abs(a), b = abs(b); while (b > 0) { tie(a, b) = make_pair(b, a % b); }return a; }
//mt19937 rnd(chrono::steady_clock::now().time_since_epoch().count());

constexpr long long INF = 1LL << 60;
constexpr int inf = 1000000007;
//constexpr long long mod = 1000000007LL;
constexpr long long  mod = 998244353;


int main()
{

	cin.tie(nullptr);
	ios::sync_with_stdio(false);

	ll n; cin >> n;
	if (n == 1) {
		cout << 2 << "\n";
		return 0;
	}
	if (n == 2) {
		cout << 3 << "\n";
		return 0;
	}
	ll res = INF;
	for (ll i = 2; i * i <= n; i++) {
		ll cur = 1;
		ll b = 1;
		while (cur <= n) {
			if (n % cur == 0 and n / cur < i) {
				chmin(res, i);
			}
			b *= i;
			cur += b;
		}
	}

	//ii(p) = p * i + i = n
	for (ll i = 1; i * i <= n; i++) {
		if (n % i == 0) {
			ll t = n / i;
			t -= 1;
			if (t > i) chmin(res, t);
		}
	}
	cout << res << "\n";
}