#include <bits/stdc++.h>
using namespace std;

int main () {
	int n, h; cin >> n >> h;
	int b[n]; int ta, best = 0;
	for (int i = 0; i < n; i++) {
		cin >> ta >> b[i];
		best = max(best, ta);
	}
	sort(b,b+n,greater<int>());
	int ans = 0;
	for (int i = 0; i < n and h > 0 and b[i] > best; i++) {
		ans++;
		h -= b[i];
	}
	if (h > 0) ans += h/best + (h%best != 0 ? 1 : 0);
	cout << ans << endl;

	return 0;
}
