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 = 0
anss = []
cnt = 0
while True:
    cnt += 1
    ans += 1
    Z = H - bunnage[cnt-1]
    zan_num = math.ceil(Z/zan)
    anss.append(zan_num + cnt)
    if cnt >= N:
        break

print(min(anss))

