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

int n,h,a[100010],b[100010],mx,ans;

int main()
{
	cin>>n>>h;
	for(int i=0;i<n;i++) cin>>a[i]>>b[i];
	
	sort(a,a+n,greater<int>());
	mx=a[0];
	
	sort(b,b+n,greater<int>());
	for(int i=0;i<n;i++) if(b[i]>mx&&h>0) {h-=b[i];ans++;}
	
	if(h>0) ans+=(h+mx-1)/mx;
	
	cout<<ans;
	
	return 0;
}