#include <bits/stdc++.h>
using namespace std;
int arr_wield[100001],arr_throw[100001];
bool mycompare(const int & a,const int & b)
{
	return a>b;
}
int main()
{
	int N,H,i,count=0,ans=0,pos_t=0;
	scanf("%d %d",&N,&H);
	for(i=0;i<N;i++)
	{
		scanf("%d %d",&arr_wield[i],&arr_throw[i]);
	}
	sort(arr_wield,arr_wield+N,mycompare);
	sort(arr_throw,arr_throw+N,mycompare);
	while(H>0)
	{
		if(arr_throw[pos_t]>arr_wieid[0])
		{
			H-=arr_throw[pos_t++];
			ans++;
		}
		else
		{
			ans=H/arr_wield[0];
			ans=H%arr_wield[0]==0?0:1;	
		    break;
		}
	}
	printf("%d",ans);
	return 0;
}