#include <bits/stdc++.h>
 
using namespace std;
 
int main() {
	int n, h;
	cin >> n >> h;
	int a, b[100001] = {};
	int ma = 0;
	for (int i = 0; i < n; ++i) {
		cin >> a >> b[i];
		ma = max(ma, a);
	}
	sort(b, b + n, greater<int>());
	int ans = 0;
	for (int i = 0; i <= n; ++i) {
		if (b[i] > ma && h > 0) {
			h -= b[i];
			ans++;
		}
	}
	if (h > 0) ans += (h + ma - 1) / ma;
	cout << ans << endl;
	return 0;
}
