import numpy as np
import sys

n, h = map(int, input().strip().split())
a = [0] * n
b = [0] * n
for i in range(n):
    a[i], b[i] = map(int, input().strip().split())

arr_a = np.array(a)
idx_a_max = arr_a.argmax()
a_max = a[idx_a_max]
b_tmp = b[idx_a_max]
b[idx_a_max] = 0
b.sort()

sum_b = 0
ans = 0

flag = False
for i in range(n - 1):
    if b[-1 - i] < a_max:
        break
    sum_b += b[-1 - i]
    ans += 1
    if sum_b > h:
        print(ans)
        flag = True
        break

if not flag:
    h_tmp = h - sum_b - b_tmp
    ans += 1
    if h_tmp > 0:
        ans += (h_tmp + a_max - 1) // a_max

    print(ans)
