import java.util.*;

class PocketAndBiscuits {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int cnt = 0;
		int biscuits = 1;
		if (n == 1) {
			System.out.println(cnt);
		} else {
			while (true) {
				cnt++;
				if (biscuits * 2 >= n) {
					break;
				}
				biscuits += biscuits;
			}
			System.out.println(cnt);
		}
	}
}