#include "bits/stdc++.h" using namespace std; using Graph = vector>; typedef long long ll; typedef pair P; #define rep(i,n) for (ll i = 0; i < (n); ++i) #define all(x) (x).begin(), (x).end() const long long mod = 1e9 + 7; ll gcd(ll a, ll b) { return b ? gcd(b, a % b) : a; } ll lcm(ll a, ll b) { return a / gcd(a, b) * b; } int main() { ll n; cin >> n; ll ans = 0; ll num = 1; while (num < n) { ans++; num *= 2; } cout << ans << endl; }