#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;

int main(){
	int n, h;
	int count = 0;
	cin >> n >> h;
	vector<int> a(n), b(n);
	for(int i = 0; i < n; i++){
		cin >> a[i] >> b[i];
	}
	sort(a.begin(), a.end());
	sort(b.begin(), b.end());
	int i = n - 1;
	while(h > 0 && b[i] > a[n-1] && i >= 0){
		h -= b[i];
		count++;
		i--;
	}
	if(h>0){
		count += (h + a.back() - 1) / a.back();
	}
	cout << count;
	return 0;
}
