import math
n, h = map(int, input().split())

katana_list = []
swing_attack = 0
for i in range(n):
    array = list(map(int, input().split()))
    if array[0] > swing_attack:
        swing_attack = array[0]
    katana_list.append(array)

katana = [katana_list[i] for i in range(n) if katana_list[i][1] > swing_attack]
katana.sort(reverse=True, key=lambda x: x[1])

for i in range(len(katana)):
    h -= katana[i][1]
    if h < 0:
        print(i+1)
        exit()

count = i + 1

count += int(math.ceil(h/swing_attack))

print(count)
