#include<bits/stdc++.h>
using namespace std;
int main()
{
	long double s=0,a;
	char t;
	while(t!='\n'&&t!='\r')
	{
	    cin>>a;
	    s+=1000*a;
	    t=getchar();
	}
	s/=1000;
	printf("%.5Lf\n",s);
}

#1&&#10 TLE，#6&&#8 WA