#include<iostream>
#include<algorithm>
using lint=int64_t;
using namespace std;

int main()
{
	int N,H;
	int a;
	int b[100010]={};
	int amax=0;
	
	cin >> N >> H;
	for(int i=0;i<N;i++)
	{
		cin >> a >> b[i];
		amax=max(amax,a);
	}
	
	sort(b,b+N,greater<int>());
	
	int ans=0;
	for(int i=0;i<N && H>0;i++)
	{
		if(b[i]>amax)
		{
			H-=b[i];
			ans++;
		}
		else
			break;
	}
	
	if(H>0)
	{
		ans+=H/amax;
		if(H%amax!=0)
			ans++;
	}
	
	cout << ans << endl;
	return 0;
}