#include <bits/stdc++.h>
using namespace std;
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) begin(v),end(v)
template<typename A, typename B> inline bool chmax(A & a, const B & b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A & a, const B & b) { if (a > b) { a = b; return true; } return false; }
using ll = long long;
using pii = pair<int, int>;
constexpr ll INF = 1ll<<30;
constexpr ll longINF = 1ll<<60;
constexpr ll MOD = 1000000007;
constexpr bool debug = false;
//---------------------------------//

int main() {
	ll N;
	cin >> N;
	
	ll ans = N - 1;
	
	FOR(len, 1, 41) {
		FOR(m, 1, 10) {
			vector<ll> num(len, m);
			
			// p 進法での n
			auto make = [](ll p, ll n) -> vector<ll> {
				vector<ll> res;
				while (n > 0) {
					res.emplace_back(n % p);
					n /= p;
				}
				reverse(ALL(res));
				return res;
			};
			
			// p 進法で比較 a <= b
			auto compare = [](const vector<ll> a, const vector<ll> b) -> bool {
				if (a.size() != b.size()) return a.size() < b.size();
				REP(i, a.size()) if (a[i] != b[i]) return a[i] < b[i];
				return true;
			};
			
			ll l = 1, r = N - 1;
			while (r - l > 1) {
				ll p = (l + r) >> 1;
				
				if (compare(make(p, N), num)) r = p;
				else l = p;
			}
			
			if (make(r, N) == num) chmin(ans, r);
		}
	}
	
	cout << ans << endl;
}