#include<bits/stdc++.h>
using namespace std;
int main()
{
	int n,h;
	cin>>n>>h;
	vector<int>a(n);
	vector<int>b(n);
	for(int i=0;i<n;i++)
	{
		cin>>a[i]>>b[i];
	}
	sort(a.begin(),a.end());
	sort(b.begin(),b.end());
	int sum=0;int i=n-1;
	while(i>=0)
	{
		if(b[i]>a[n-1])
		{
			h-=b[i];
			sum++;
		}
		if(h<=0)
		{
			cout<<sum;
			return 0;
		}
		
		i--;
	}
	cout<<sum+(h+a[n-1]-1)/a[n-1];
	return 0;
}