#include<bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i=0; i<(int)(n); i++)
#define all(vec) vec.begin(), vec.end()
#define MOD 1000000007
#define int int64_t

signed main(){
	int n,h;cin>>n>>h;
	priority_queue<int> q;
	vector<pair<int,int>> v(n);
	rep(i,n){
		int a,b;cin>>a>>b;
		v[i]=make_pair(a,b);
	}
	sort(all(v),greater<>());
	int s=v[0].first;
	for(int i=1; i<n; i++){
		q.push(v[i].second);
	}
	int ans=0;
	q.push(0);
	while(s<q.top()&&h>0){
		h-=q.top();q.pop();
		ans++;
	}
	if(h>0){
		h-=v[0].second;
		ans++;
	}
	if(h>0)ans+=(h+s-1)/s;
	cout<<ans<<endl;
}