#include<bits/stdc++.h>
using namespace std;

int main(){
	cin.tie(0),ios::sync_with_stdio(false);
	int n,h; cin>>n>>h;
	vector<int>b(n);
	int amx=0;
	for(auto&b:b){
		int a; cin>>a>>b;
		amx=max(amx,a);
	}
	sort(b.begin(),b.end(),greater<int>());
	int ans=0;
	for(auto&b:b){
		if(b<=amx||h<=0)break;
		h-=b,++ans;
	}
	if(h>0)ans+=(h+amx-1)/amx;
	cout<<ans<<"\n"s;
}