#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000

int main(){
	
	long long n;
	cin>>n;
	
	long long cur = 1LL;
	int ans = 0;
	while(cur < n){
		ans++;
		cur<<=1;
	}
	cout<<ans<<endl;
	
	return 0;
}