#include<bits/stdc++.h>
using namespace std;
int n,h;
int a[100000],b[100000];
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);
	int ans=0;
	for(int i=n-1;i>=0;i--)
	{
		if(h<=0)
		{
			cout<<ans;
			return 0;
		}
		if(b[i]>a[n-1])
		{
			ans++;
			h-=b[i];
		}
		else
		break;
	}
	ans+=(h+a[n-1]-1)/a[n-1];
	cout<<ans;
	return 0;
}