#!/usr/bin/env python3
import sys


def solve(N: int, H: int, a: "List[int]", b: "List[int]"):
    ab = sorted([[i, a[i], b[i]] for i in range(N)], key=lambda x:x[2], reverse=True)
    am = max(a)
    
    ans = 0
    cnt = 0
    bma = sorted([i for i in b if i >= am], reverse=True)
    if(sum(bma) >= H):
        while(cnt <= H):
            try:
                cnt -= bma.pop(0)
            except IndexError:
                print(ans)
                exit()
            ans += 1
        print(ans)
        exit()

    # b[i]がamより大きいかぎり消し続ける
    from math import ceil
    print(ceil((H - sum(bma))/am)+len(bma))

    return


# Generated by 1.1.4 https://github.com/kyuridenamida/atcoder-tools  (tips: You use the default template now. You can remove this line by using your custom template)
def main():
    def iterate_tokens():
        for line in sys.stdin:
            for word in line.split():
                yield word
    tokens = iterate_tokens()
    N = int(next(tokens))  # type: int
    H = int(next(tokens))  # type: int
    a = [int()] * (N)  # type: "List[int]" 
    b = [int()] * (N)  # type: "List[int]" 
    for i in range(N):
        a[i] = int(next(tokens))
        b[i] = int(next(tokens))
    solve(N, H, a, b)

if __name__ == '__main__':
    main()
