import strscans

let
  (_, a, b, c) = stdin.readAll.scanTuple"$i $i $i"
  cma = c mod a
  cda = c div a
  bcma = (b + c) mod a
  bcda = (b + c) div a

if cma == 0 and b >= c:
  echo cda
  if bcma == 0:
    echo bcda
  quit()

if bcma == 0:
  echo bcda
  quit()

echo -1