#include<iostream> // cin\cout\endl #include<cstdio> //scanf()\printf() #include<cstring> // strcpy()\strcat()\strcmp()\strlen()\memset() #include<cmath> //sqrt()\pow()\abs()\ceil()\floor()\max()\min() using namespace std; int main(){ char a[64]; double s=0,x=1; int j=0; cin>>a; while(a[j]!='.'){ j++; } for(int i=j-1;i>=0;i--){ s+=(a[i]-'0')*x; x*=2; } x=0.5; for(int i=j+1;i>=0;i--){ s+=(a[i]-'0')*x; x/=2; } cout<<s; return 0; }