import java.util.*;
 

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int ans=0;
		int a=1;
		while(a<n){
			ans++;
			a*=2;
			
		}
		System.out.println(ans);
	}
}