def main():
    N, H = map(int, input().split())
    a = 0
    b = []
    for i in range(N):
        t = list(map(int, input().split()))
        a = max(a, t[0])
        b.append(t[1])
    b = sorted(b, reverse=True)
    # print(a)
    # print(b)
    i = 0
    while b[i] > a:
        H -= b[i]
        i += 1
        if i >= N:
            break
    if H%a == 0:
        print(i + H//a)
    else:
        print(i + H//a + 1)

if __name__ == "__main__":
    main()
