#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
int main() {
	int n;ll h;cin>>n>>h;
	ll a[114514],b=0;for(int i=0;i<n;i++){ll k;cin>>k>>a[i];b=max(b,k);}
	sort(a,a+n);
	ll ans=0;
	for(int i=n-1;i>=0&&a[i]>=b;i--){h-=a[i];ans++;if(h<=0)goto heaven;}
	if(h%b!=0)h+=b-(h%b);
	ans+=h/b;
	heaven:cout<<ans<<endl;
	return 0;
}