#include<bits/stdc++.h> using namespace std; int main(){ string s; cin >> s; int len = s.size(); double m = 0; int idx = s.find('.'); for(int i = 0;i < len;i++){ if(i < idx){ m = m + (s[i] - '0') * pow(2,idx - i - 1); }else if(i > idx){ m = m + (s[i] - '0') * pow(2,idx - i); } } cout << m; return 0; }