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

int main(){
	ll n,h,a[100500],b[100500],cnt=0,dam=0;
	cin>>n>>h;
	for(int i=0; i<n; i++)cin>>a[i]>>b[i];
	sort(a,a+n);
	sort(b,b+n);
	for(int i=n-1; i>=0; i--){
		if(b[i]<a[n-1])break;
		dam+=b[i],cnt++;
		if(dam>=h){
			cout<<cnt<<endl;
			return 0;
		}
	}
	h-=dam;
	if(h%a[n-1])cout<<cnt+h/a[n-1]+1<<endl;
	else cout<<cnt+h/a[n-1]<<endl;
}
