import math

N, H = map(int, input().split())
ab = [list(map(int, input().split())) for i in range(N)]
zan = max(ab)
zan = zan[0]
ab.sort(reverse=True, key=lambda x:x[1])

bunnage = [ab[0][1]]
for i in range(1,N):
    bunnage.append(bunnage[i-1]+ab[i][1])

ans = []

for i in range(len(bunnage)):
    Z = H - bunnage[i]
    zan_num = math.ceil(Z/zan)
    ans.append(i+1+zan_num)

print(min(ans))


