#include<stdio.h>
int flg;
int f(int x){
	if(x==1)return 1;
	flg |= x&1;
	return 1 + f(x>>1);
}
int main(){
	int n;
	scanf("%d", &n);
	printf("%d\n", f(n) - !flg);
	return 0;
}