#include<iostream>
#include<algorithm>

using namespace std;

int main(){
	int N, H, B[100000];
	int amax = 0;
	int cnt = 0;
	cin >> N >> H;
	for (int i = 0; i < N; i++){
		int a;
		cin >> a >> B[i];
		amax = max(a, amax);
	}
	sort(B, B + N);
	for (int i = N - 1; i >= 0; i--){
		if (B[i]>=amax) {
			H -= B[i];
			cnt++;
		}
		if (H <= 0){
			cout << cnt << endl;
			return 0;
		}
	}
	cout << cnt + (H + amax - 1) / amax << endl;
	return 0;
}
