import java.util.Scanner; public class Main{ public static void main(String[] args) { //System.out.println("数字"); Scanner scanner = new Scanner(System.in); int N = scanner.nextInt(); scanner.close(); int n = 0; int y; boolean flag = true; // while文の繰り返し回数を20未満とした while(flag) { y = N - (int) Math.pow(2, n); if(y <= 0) { break; } if(n > 20) { flag = false; } n++; } System.out.println(n); } }