program aaa;

{$APPTYPE CONSOLE}

var t:array [1..10] of integer;
s:real;
i:integer;
begin
for i:=1 to 10 do read(t[1]);
s:=0;
for i:=1 to 10 do s:=s+t[1];
writeln(s/100);
readln;
readln;
end.