#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main() {
	ll N, H;
	cin >> N >> H;
	ll a[N], b[N];
	for (ll i = 0; i < N; i++) {
		cin >> a[i] >> b[i];
	}
	sort(a, a + N);
	sort(b, b + N);
	ll a_max = a[N - 1];
	ll cnt = 0;
	for (ll i = N - 1; i >= 0; i--) {
		if (a_max <= b[i]) {
			H -= b[i];
			cnt++;
		}
		if(H<=0){cout<<cnt<<endl; return 0;}
    }
	while (H > 0) {
		H -= a_max;
		cnt++;
	}
	cout << cnt << endl;
}