var
A, B, K, R : longint;
begin
readln(A, B);
if (A mod 2 = 1) and (B mod 2 = 1) then
writeln('-1');
if (A mod 2 = 0) and (B mod 2 = 0) and
((A div 2 <> B) or (B div 2 <> A)) then
writeln('-1');
if (A mod 2 = 0) and (B mod 2 = 0) and
((A div 2 = B) or (B div 2 = A)) then
if A > B then
writeln(B, '0')
else
writeln('0', A);
if (A mod 2 = 1) and (B mod 2 = A) then begin
A := A-1;
B := B-2;
if (A div 2 = B) or (B div 2 = A) then
if A > B then
writeln(B, '0')
else
writeln('0', A);
end;
if (B mod 2 = 1) and (A mod 2 = B) then begin
B := B-1;
A := A-2;
if (B div 2 = A) or (A div 2 = B) then
if B > A then
writeln(B, '0')
else
writeln('0', A)
end;
end.
На Всё что могу.
