#include <iostream>
#include <algorithm>
using namespace std;
int main(){
	int n, h;
	int a[100000], b[100000];
	cin >> n >> h;
	for(int i = 0;i < n;i++){
		cin >> a[i] >> b[i];
	}
	sort(a, a + n, greater<int>());
	sort(b, b + n, greater<int>());
	int k = 0;
	int j = 0;
	while(1){
		if(k < n && b[k] > a[0]){
			j += b[k];
			k++;
			if(j >= h){
				cout << k << endl;
				return 0;
			}
		}else{
			break;
		}
	}
	k += ((h - j - 1) / a[0] + 1);
	cout << k << endl;
}