#include "bits/stdc++.h"

using namespace std;

void solve()
{
	int N, H;
	cin >> N >> H;
	vector<pair<int, int>> as(N), bs(N);
	vector<int> mp(N);
	for (int i = 0; i < N; i++)
	{
		cin >> as[i].first >> bs[i].first;
		as[i].second = i;
		bs[i].second = i;
		mp[i] = bs[i].first;
	}
	sort(as.rbegin(), as.rend());
	sort(bs.rbegin(), bs.rend());
	int a = as[0].first, i = as[0].second, ans = 0;
	H -= mp[i];
	for (auto p : bs)
	{
		if (p.second == i) continue;
		if (H <= 0 || a >= b) break;
		H -= b;
		ans++;
	}
	if (H > 0) ans += ceil(H / a);
	cout << ans << endl;
}

int main(void)
{
	solve();
	//cout << "yui(*-v・)yui" << endl;
	return 0;
}
