#include<bits/stdc++.h>
using namespace std;
const int maxn=1e5+5;
struct sword{
	int x,y;
	friend operator <(sword a,sword b){
		return a.y>b.y;
	}
}a[maxn];
int main()
{
	int n,q;cin>>n>>q;int max_=0;
	for(int i=1;i<=n;i++)
	{
		cin>>a[i].x>>a[i].y;
		max_=max(a[i].x,max_);
	}
	sort(a+1,a+n+1);
	int ans=0;
	int i=1;
	while(a[i].y>=max_)
	{
		q-=a[i].y;ans++;
		if(q<=0)
		{
			printf("%d\n",ans);
			return 0;
		}
		i++;
	}
	while(q>0)
	{
		q-=max_;ans++;
	}
	printf("%d\n",ans);
	return 0;
}