n, H = map(int, input().split())
amax = 0
ab = []

for i in range(n):
    v1, v2 = map(int, input().split())
    amax = max(amax, v1)
    ab.append([v1, v2])

ab.sort(key=lambda x: x[1], reverse=True)
cnt = 0

#print(ab)

while H > 0 and len(ab) > 0:
    if ab[0][1] > amax:
        H -= ab[0][1]
        del ab[0]
        cnt += 1
    # elif len(ab) == 1 and ab[0][1] < H:
    #     if ab[0][0] == amax:
    #         cnt += H // amax
    #         break
    #     else:
    #         H -= ab[0][0]
    #         cnt += 1
    else:
        cnt += H // amax
        break

print(cnt)

