#include<iostream>
#include<vector>
#include<queue>
using namespace std;
int main(void){
	int n,h;
	cin>>n>>h;
	priority_queue<int> a,b;
	int c,d,ans=0;
	for(int i=0;i<n;i++){
		cin>>c>>d;
		a.push(c);
		b.push(d);
	}
	c=a.top();
	while(h>0&&!b.empty()&&b.top()>c){
		h-=b.top();
		ans++;
		b.pop();
	}
	if(h>0){
		ans+=h/c;
	}
	if(h%c!=0&&h>0)ans++;
	cout<<ans<<endl;
	return 0;
}