#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
#define FOR(i,a,b) for(int i=(a);i<(int)(b);i++)
#define rep(i,n) FOR(i,0,n)
#define ALL(x) (x).begin(),(x).end()

int main() {
    int n; cin >> n;
    int c = 1;
    ll ans = 0;
    while(c < n) {
        c *= 2;
        ++ans;
    }

    cout << ans << "\n";

    return 0;
}