C++ :

#include<bits/stdc++.h>
using namespace std;
double n;
int a;
int main()
{
cin>>n;
n=n*2.8;
while(n>=0.5)
	{
	a++;
	n/=2;
	}
cout<<a;
return 0;
}

Python :

# coding=utf-8
n=input()
h=float(n)*2.8
ans=0
while (h>=0.5):
    h=h/2
    ans=ans+1
print(ans)