#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
#define inf 1000000007


int main() {
	ll n,h,MAX=0;
	vector<ll> b;
	cin>>n>>h;
	for(int i=0;i<n;i++){
		ll l,r;
		cin>>l>>r;
		MAX=max(MAX,l);
		b.push_back(r);
	}
	sort(b.begin(),b.end());reverse(b.begin(),b.end());
	ll ans=0,k=0;
	while(h>0){
		h-=b[k];
		ans++;
		k++;
		if(k==n||b[k]<MAX){
			break;
		}
	}
	cout << ( h>0 ? ans+(h+MAX-1)/MAX:ans);
}