Const
n=300;
var
a:array[1..n]of integer;
i,k:integer;
s:real;
begin
i:=1;
readln(a[i]);
while a[i]<>0 do
begin
if (abs(a[i])>=100)and(abs(a[i])<=500)then<br> begin
k:=k+1;
s:=s+a[i];
end;
readln(a[i]);
end;
if k<>0 then
writeln('Sr = ',s/k:4:2)
else
writeln('Net');
end.