#include <cstdio>
#include <cmath>
#include <algorithm>
using namespace std;
typedef long long ll;
ll a[100006], b[100006];
int main(){
	ll i, j;
	ll n, h;
	ll res=0;
	
	scanf("%lld %lld", &n, &h);
	for(i=1; i<=n; i++)
		scanf("%lld %lld", &a[i], &b[i]);
	
	sort(a+1, a+1+n);
	sort(b+1, b+1+n);
	for(i=n; b[i]>a[n] and h>0; i--){
		h-=b[i];
		res++;
	}
	if(h>0)
		printf("%lld", res+h/a[n]+!!(h%a[n]));
	else
		printf("%lld", res);
	return 0;
}