#include<iostream>
#include<vector>
#include<algorithm>
#include<iomanip>
using namespace std;
#define OVERLOAD_REP(_1, _2, _3, name, ...) name
#define REP1(i, n) for (auto i = std::decay_t<decltype(n)>{}; (i) != (n); ++(i))
#define REP2(i, l, r) for (auto i = (l); (i) != (r); ++(i))
#define rep(...) OVERLOAD_REP(__VA_ARGS__, REP2, REP1)(__VA_ARGS__)
#define REP(i, l, r) rep(i, l, r+1)
#define all(x) (x).begin(),(x).end()
#define inf 1000000000
using ll = long long;
using P = pair<int,int>;
using Graph = vector<vector<int> >;

int main() {
    // 高速化
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    // 小数点の出力桁数を指定
    cout << fixed << setprecision(10);

    // メイン
    int N;
    cin >> N;
    int ans = 0;
    while(true) {
        N = (N+1)/2;
        ans++;
        if(N == 1) break;
        //int cur = 0;
        //for(int i = 0; (1 << i) < N; i++) cur = (1 << i);
        //N = cur;
    }
    cout << ans << endl;

    return 0;
}