#include using namespace std; using ll = long long; using ld = long double; using P = pair; using Pld = pair; using Vec = vector; using VecP = vector

; using VecB = vector; using VecC = vector; using VecD = vector; using VecS = vector; template using Vec2 = vector>; #define REP(i, m, n) for(ll i = (m); i < (n); ++i) #define REPN(i, m, n) for(ll i = (m); i <= (n); ++i) #define REPR(i, m, n) for(ll i = (m)-1; i >= (n); --i) #define REPNR(i, m, n) for(ll i = (m); i >= (n); --i) #define rep(i, n) REP(i, 0, n) #define repn(i, n) REPN(i, 1, n) #define repr(i, n) REPR(i, n, 0) #define repnr(i, n) REPNR(i, n, 1) #define all(s) (s).begin(), (s).end() #define pb push_back #define fs first #define sc second template bool chmax(T &a, const T b){if(a < b){a = b; return true;} return false;} template bool chmin(T &a, const T b){if(a > b){a = b; return true;} return false;} template ll pow2(const T n){return (1LL << n);} template void cosp(const T n){cout << n << ' ';} void co(void){cout << '\n';} template void co(const T n){cout << n << '\n';} template void co(pair p){cout << p.fs << ' ' << p.sc << '\n';} template void co(const vector &v){for(T i : v) cosp(i); co();} template void co(initializer_list v){for(T i : v) cosp(i); co();} void ce(void){cerr << '\n';} template void ce(const T n){cerr << n << '\n';} template void cesp(const T n){cerr << n << ' ';} template void ce(initializer_list v){for(T i : v) cesp(i); ce();} void sonic(){ios::sync_with_stdio(false); cin.tie(0);} void setp(const ll n){cout << fixed << setprecision(n);} constexpr int INF = 1e9+1; constexpr ll LINF = 1e18L+1; constexpr ll MOD = 1e9L+7; constexpr ll MOD_N = 998244353; constexpr ld EPS = 1e-11; const double PI = acos(-1); int main(void){ ll a; cin >> a; ll ans = LINF; REPN(i, 2, a) { if(i >= 1e6) break; ll t = i, cnt = 1; while(t < a) { t *= i; cnt++; } chmin(ans, i * cnt); } co(ans); return 0; }