[백준] 27961번 고양이는 많을수록 좋다 (bronze 1

import java.util.*;
import java.io.*;

public class Main{
    public static void main(String[] args) throws IOException{
        BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
        BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(System.out));

        long n=Long.valueOf(br.readLine());
        long temp=1l;
        int answer=1;
        while(temp<n){
            temp*=2;
            answer++;
        }
        bw.write(n==0 ? answer-1+"" : answer+"");
        bw.flush();
    }
}