import sys

d = input()
h = []
for i in xrange(3):
  h.append(input())

def is_finish(H):
  if (len(set(H)) == 3 and (min(H) == H[1] or max(H) == H[1])):
    return True
  else:
    return False

def is_impossible(H):
  if d == 0:
    return True
  else:
    return False

def mod_min(H):
  res = 0
  if H[0] == H[2]:
    H[0] = max(0, H[0] - d)
    res += 1
  #print H
  diff = abs(H[1] - min(H[0], H[2]))
  H[1] -= (diff / d + 1) * d
  H[1] = max(H[1], 0)
  if len(set(H)) == 3 and min(H) == H[1]:
    return res + diff / d + 1
  return 1e+18+7

def mod_max(H):
  diff = abs(H[1] - max(H[0] ,H[2]))
  i = 0 if max(H[0],H[2]) == H[0] else 2
  H[i] -= (diff / d + 1) * d
  H[i] = max(H[i], 0)
  if len(set(H)) == 3 and max(H) == H[1]:
    #print "max"
    return diff / d + 1
  return 1e+18+7

def solve():
  if is_finish(h):
    print 0
    return
  if is_impossible(h):
    print -1
    return
  res1 = mod_min(h[:])
  res2 = mod_max(h[:])
  if min(res1, res2) != 1e+18 + 7:
    print min(res1, res2)
  else:
    print -1
  return

def main():
  solve()

solve()