import math
from math import gcd,pi,sqrt
INF = float("inf")

import sys
sys.setrecursionlimit(10**6)
import itertools
from collections import Counter,deque
def i_input(): return int(input())
def i_map(): return map(int, input().split())
def i_list(): return list(i_map())
def i_row(N): return [i_input() for _ in range(N)]
def i_row_list(N): return [i_list() for _ in range(N)]
def s_input(): return input()
def s_map(): return input().split()
def s_list(): return list(s_map())
def s_row(N): return [s_input for _ in range(N)]
def s_row_str(N): return [s_list() for _ in range(N)]
def s_row_list(N): return [list(s_input()) for _ in range(N)]

import string

def main():
    N,H = i_map()
    l = []
    for _ in range(N):
        a,b = i_map()
        l.append([a,b])
    t = [list(i) for i in zip(*l)]
    ans = 0

    M = max(t[0])
    throw = 0
    for i in sorted(t[1]):
        if i > M:
            throw += i
            H -= i
            ans += 1
            if H <= 0:
                print(ans)
                exit()
    i = t[0].index(M)
    # H += t[1][i]
    if H%M == 0:
        ans += H//M
    else:
        ans += H//M+1
    print(ans)


if __name__=="__main__":
    main()
