#include <iostream>
#include <algorithm>

using namespace std;
pair<int,int> a[200005]; 
int main()
{
	int n,h;
	cin>>n>>h;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i*2-1].first>>a[i*2].first;
		a[i*2-1].second=1;
		a[i*2].second=2;
	}
	sort(a+1,a+1+2*n,greater<pair<int,int> >() );
	int res=0;
	for(int i=1;i<=2*n;i++)
	{
		if(a[i].second==2) {h-=a[i].first;res++;if(h<=0) break;}
		else 
		{res+=(h-1)/a[i].first+1;break;}
	}
	cout<<res<<endl;
	return 0;
} 