import java.util.Scanner;

public class PocketBiscuit{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();
        if(N == 1){
            System.out.println(0);
            System.exit(1);
        }
        int num_bis = 1;
        int num_hit = 0;
        while(true){
            if(num_bis*2<N){
                num_bis = num_bis*2;
                num_hit++;
            }else{
                System.out.println(num_hit+1);
                break;
            }
        }
    }
}