#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(){ double x=1,s=0; char a[64]; cin>>a; int l,j=strlen(a); while(a[l]!='.') l++; for(int i=l-1;i>=0;i--){ s+=(a[i]-'0')*x; x*=2; } x=0.5; for(int i=l+1;i<j;i++){ s+=(a[i]-'0')*x; x/=2; } cout<<s; return 0; }