#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
int main(){
	int n,h; cin>>n>>h;
	vector<int> a(n),b(n);
	int maxa=0;
	for(int i=0;i<n;i++) {
		cin>>a[i]>>b[i];
		maxa=max(maxa,a[i]);
	}
	sort(b.begin(),b.end(),greater<int>());
	int i=0;
	int ans=0;
	while(b[i]>maxa){
		h-=b[i];
		ans++;
		i++;
		if(h<=0){
			cout << ans << endl;
			return 0;
		}
	}
	ans+=h/maxa+(h%maxa>0?1:0);
	cout << ans << endl;
	return 0;
}
