#include <bits/stdc++.h>
using namespace std;

int main(int argc, char const *argv[])
{
	int n,h;
	cin>>n>>h;
	int a[n],b[n];
	for (int i = 0; i < n; ++i)
	{
		cin>>a[i]>>b[i];
	}
	sort(a,a+n);
	reverse(a,a+n);
	sort(b,b+n);
	reverse(b,b+n);
	int ans=0;
	for (int i = 0; i < n; ++i)
	{
		if (a[0]<b[i])
		{
			++ans;
			h-=b[i];
			if (h<=0)
			{
				break;
			}
		}
		else
		{
			break;
		}
	}
	if (h>0)
	{
		ans+=(h+a[0]-1)/a[0];
	}
	cout<<ans<<endl;
	return 0;
}
