def main():
    a, b, c, d = map(int, input().split(' '))
    amount = 0
    while True:
        a -= 1
        b -= c
        d -= c+1
        if a < 0 or b < 0 or d < 0:
            break
        amount += 1
    print(amount)

if __name__ == '__main__':
    main()