#include <iostream>
#include <algorithm>
using namespace std;
const int N=1e5+5;
int b[N];

bool cmp(int x,int y)
{
	return x>y;
}

int main()
{
	int n,h,ma=0;
	cin>>n>>h;	
	for(int i=0;i<n;i++){
		int t;
		cin>>t>>b[i];
		if(t>ma)
			ma=t;
	}
	sort(b,b+n,cmp);
	int m=0,s=0;
	while(h>0){
		if(b[m]>=ma){
			h-=b[m];
			s++;
			m++;
		}
		else{
			s+=h/ma;
			if(h%ma>0)
				s++;
			break; 
		}
	}
	cout<<s<<endl;
	return 0;	
} 