// Цикл while
var
n, i, s: integer;
begin
readln(n);
s := 2 * n;
i := 1;
while i <= n do <br> begin
s := s + 2 * (n + i);
i := i + 1;
end;
writeln(s);
end.
//цикл Repeat
var
n, i, s: integer;
begin
readln(n);
s := 2 * n;
i := 1;
repeat
s := s + 2 * (n + i);
i := i + 1;
until i > n;
writeln(s);
end.
// Цикл for
var
n, i, s: integer;
begin
readln(n);
s := 2 * n;
for i:=1 to n do
s := s + 2 * (n + i);
writeln(s);
end.