#!/usr/bin/env python3
def is_kadomatsu(a, b, c):
    return (a < b and b > c) or (a > b and b < c)
def make_lt(a, b):
    global d
    if b == 0:
        return None
    else:
        return max(0, (a - (b-1) + d-1) // d)
d = int(input())
h1 = int(input())
h2 = int(input())
h3 = int(input())
if d == 0:
    if is_kadomatsu(h1, h2, h3):
        ans = 0
    else:
        ans = -1
else:
    ans = float('inf')
    if h2 > 0:
        ans = min(ans, make_lt(h1, h2) + make_lt(h3, h2))
    if h1 > 0 and h3 > 0:
        ans = min(ans, max(make_lt(h2, h1), make_lt(h2, h3)))
    if ans == float('inf'):
        ans = -1
print(ans)