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