#include<bits/stdc++.h>
#define ll long long
using namespace std;
ll n,h,mi,i,a[101010],b[101010],hs;
int main()
{
	cin>>n>>h;
	for(i=1;i<=n;i++)
	{
		cin>>a[i]>>b[i];
		mi=max(mi,a[i]);
	}
	sort(b+1,b+1+n);
	for(i=n;i>=1;i--)
	{
		if(b[i]<mi)
			break;
		h-=b[i];
		hs++;
		if(h<=0)
		{
			cout<<hs<<"\n";
			return 0;
		}
	}
//	cout<<h<<" "<<mi<<"\n";
	hs+=ceil(double(h)/double(mi));
	cout<<hs<<"\n";
}