#include<iostream>
#include<algorithm>
#include<cstdio>
using namespace std;
int n,v,ans,a[100005],b[100005];
int main()
{
	scanf("%d%d",&n,&v);
	for (int i=1;i<=n;i++)
		scanf("%d%d",&a[i],&b[i]);
	sort(a+1,a+n+1);
	sort(b+1,b+n+1);
	for (int i=n;i>=1&&b[i]>a[n]&&v>0;v-=b[i],i--,ans++);
	if (v>0) ans=ans+v/a[n]+(v%a[n]!=0);
	printf("%d\n",ans);
}