import java.io.*;

class Main{

static final PrintWriter out=new PrintWriter(System.out);

public static void main(String[] args) throws IOException{
BufferedReader br=new BufferedReader(new InputStreamReader(System.in));
String line="";
double ans=0;
while((line=br.readLine())!=null&&!line.isEmpty()){
double d=Double.parseDouble(line);
ans+=d;
}
out.printf("%.10f",ans);
out.flush();
}
}