a, b, c, d = map(int, input().split())

if b < c:
    print(0)
    exit()

vegi_num = 0
for i in range(1, a + 1):
    meet_required = i * c

    if i + meet_required > d:
        break

    if b >= meet_required:
        vegi_num = i
    else:
        continue

print(vegi_num)