Program n1;
var a,k,sum: integer;
f: text;
begin
assign(f,'input.txt');
reset(f);
sum:=0;
k:=0;
while not eof(f) do
readln(f,a)
sum:=sum+a;
k:=k+1;
end;
close(f);
assign(f,'output.txt');
rewrite(f);
write(f,sum/k);
end.
Program n1;
var a,k,sum: integer;
f: text;
begin
assign(f,'input.txt');
reset(f);
sum:=0;
k:=0;
while not eof(f) do
begin
readln(f,a)
sum:=sum+a;
k:=k+1;
end;
close(f);
assign(f,'output.txt');
rewrite(f);
write(f,sum/k);
close(f);
end.