import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class No47 {

	public static void main(String[] args) throws IOException, NumberFormatException{
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		int count = 0;
		for (int i = 0; Math.pow(2,i) < n; i++) count++;
		System.out.println(count);
	}
}