def main():
  a, b, c, d = map(int, input().split(' '))
  vegetables = 0
  meats = 0
  total = 0
  for i in range(1, a + 1):
    vegetables += 1
    meats += c
    total = vegetables + meats
    if meats > b or total > d:
      print(vegetables - 1)
      return
  print(vegetables)


if __name__ == '__main__':
  main()