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