
N,H = map(int,input().split())

a = []
b = []
finish = 0

for i in range(1,N+1):
    elem1, elem2 = map(int,input().split())
    a.append(elem1)
    b.append(elem2)

maxB = max(b)
maxA = max(a)
sum = maxB
b.remove(maxB)
count = 1
for elem in b:
    if elem > maxA:
        sum = sum + elem
    #print(sum)
        count += 1
        if sum > H:
            finish = 1
            break


#print(sum)
if finish == 0:
    dev = int((H - sum)/maxA)
    count = count + dev
    sum = sum + dev * maxA
    if sum < H:
        count += 1

print(count)
