import sys
from math import factorial
input = sys.stdin.readline

N, H = map(int, input().split())
L = [list(map(int, input().split())) for _ in range(N)]
normal_max = max([v[0] for v in L])
normal_max_index = 0
for i in range(N):
    if normal_max == L[i][0]:
        normal_max_index = i
        break

c = 0
for i in range(N):
    v = L[i]
    if v[1] >= normal_max and i != normal_max_index:
        c += 1
        H -= v[1]
if H <= 0:
    print(c)
    sys.exit()

if H <= L[normal_max_index][1]:
    print(c + 1)
else:
    H -= L[normal_max_index][1]
    if H % normal_max == 0:
        print(c + 1 + H // normal_max)
    else:
        print(c + 2 + H // normal_max)