#include <bits/stdc++.h>
using namespace std;
const int SIZE=100005;

bool cmp(int x,int y);

int n,hp,t=1,ans=0,w,b[SIZE],wic;

int main()
{
	cin>>n>>hp;
	for (int i=1;i<=n;i++){
		cin>>w>>b[i];
		wic=max(w,wic);
	}
	sort(b+1,b+n+1,cmp);
	
	while (b[t]>wic){
		hp-=b[t++];
		ans++;
		if (hp<=0){
			cout<<ans;
			return 0;
		}
	}
	if (hp%wic==0) cout<<ans+hp/wic;
	else		   cout<<ans+hp/wic+1;
	
	return 0;
}

bool cmp(int x,int y)
{
	return x>y;
}