#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
#define rep(i,n) for(int i=0;i<(n);i++)
#define reps(i,f,n) for(int i=(f);i<(n);i++)
#define all(v) (v).begin(),(v).end()
#define P(x) cout <<x << endl;


int main(){
    long long int n;
    cin >> n;
    int c =0;
    while(n>1) n = (n+1)/2,c++;
    P(c);
}