#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
ll n,h,max,x;
int main(){
	cin >> n >> h;
	ll a[n],b[n];
	for(int i=0;i<n;i++)
		cin >> a[i] >> b[i];
	sort(a,a+n,greater<int>());
	sort(b,b+n,greater<int>());
	for(int i=0;i<n;i++){
		if(h<=0){
			cout << x;
			return 0;
		}
		if(b[i]>a[0]){
			h-=b[i];
			x++;
		}
		else break;
	}
	if(h<=0)cout << x;
	else if(h%a[0]==0)cout << x+h/a[0];
	else cout << x+h/a[0]+1;
	return 0;
}