#include "bits/stdc++.h"
using namespace std;
int main()
{
	int n, h, mx, total = 0;
	scanf("%d %d", &n, &h);
	vector<int> a(n), b(n);
	for(int i = 0; i < n; i++)
	{
		scanf("%d %d", &a[i], &b[i]);
	}
	mx = *max_element(a.begin(), a.end());
	sort(b.begin(), b.end(), greater<int>());
	for(int i = 0; h > 0; total++)
	{
		if(i < n && mx < b[i])
		{
			h -= b[i];
			i++;
		}
		else
		{
			total += h / mx + (h % mx ? 1 : 0);
			break;
		}
	}
	printf("%d\n", total);
}