import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        while (in.hasNextInt()) { // 注意 while 处理多个 case
            int a = in.nextInt();
            String s = Integer.toBinaryString(a);
            String[] ary = {"1","11","111","1111","11111","111111","1111111","11111111"};
            int num = 0;
            for(int i = 0;i <8;i++){
                if(s.contains(ary[i])){
                    num = ary[i].length();
                }
            }
            
            System.out.println(num);
        }
    }
}