var
a: array [1..30] of integer;
i, k: integer;
begin
for i := 1 to 30 do
begin
a[i] := i;
writeln('a[', i, '] => ', a[i]);
end;
writeln();
for i := 1 to 15 do
begin
k := a[i];
A[i] := A[31 - i];
A[31 - i] := k;
end;
for i := 1 to 30 do
writeln('a[', i, '] => ', a[i]);
end.