#include<iostream>
#include<vector>
#include<bitset>
#include<algorithm>
#include<cmath>
using namespace std;
int main(){ 
    long long int n,ans=1,sum=1;
    cin >> n;
    if(n==1){
        cout << 0;
        return 0;
    }
    while(1){
        sum*=2;
        if(sum>=n)   break;
        ans++;
    }
    cout << ans;
    return 0;
}