#include <bits/stdc++.h>
using namespace std;
string dj(int n)
{
    string s="";
    while (n!=0)
    {
        s=s+char(n%10+64);
        n=n/10;
    }
    return s;
}
int main()
{
    int n;
    string s="";
    cin>>n;
    s=s+dj(n);
    while (n!=0)
    {
        n=n/2;
        s=s+dj(n);
    }
    cout<<s.size()<<endl;
    return 0;
}
/**************************************************************
	Problem: 1562
	User: lijinkai
	Language: C++
	Result: Accepted
	Time:37 ms
	Memory:2076 kb
****************************************************************/