import java.util.Scanner;

class no47{
    public static void main(String args[]){
	Scanner sc = new Scanner(System.in);

	int N = Integer.parseInt(sc.next());

	int biscuits = 1;

	int num = 0;

	while(true){
	    if( biscuits == N){
		break;
	    }
	    else if( biscuits * 2 <= N ){
		biscuits *= 2;
		num++;
	    }
	    else{
		num++;
		break;
	    }
	}

	System.out.println(num);

    }
}