#include<cstdio>
#include<iostream>
using namespace std;
int main(){
	double h,sum=0.0;
	int i=1;
	scanf("%lf",&h);
	do{
		sum++;
		h=h/2;
		if(i!=100) sum++;
		i++;
	}while(h<0.5);
	printf("%.7lf",sum);
}
/**************************************************************
	Problem: 1062
	User: zouliangyin
	Language: C++
	Result: Time Limit Exceed
****************************************************************/