#include<iostream>
#include<algorithm>
using namespace std;
long n,h,a[1<<17],b[1<<17];
int main()
{
	cin>>n>>h;
	for(int i=0;i<n;i++)cin>>a[i]>>b[i];
	sort(a,a+n);sort(b,b+n);
	long cnt=0;
	for(int i=n;i--;)
	{
		if(b[i]<a[n-1])break;
		cnt++;
		h-=b[i];
		if(h<=0)break;
	}
	cout<<(cnt+(h>0?(h+a[n-1]-1)/a[n-1]:0))<<endl;
}