#define _USE_MATH_DEFINES
#include<stdio.h>
#include<string>
#include<iostream>
#include<cctype>
#include<cstdio>
#include<vector>
#include<stack>
#include <algorithm>
#include<math.h>
#include<set>
#include<map>
#include<iomanip>
using namespace std;



int main(){
	
int n;
cin>>n;
long long int a=0,b=1;
while(b<n){
	a++;
	b*=2;
}
cout<<a<<endl;;
	return 0;
}