#include <bits/stdc++.h>
#define ll long long
#define mp make_pair
#define pb push_back
#define INF 0x3f3f3f3f
using namespace std;
int n,h,a[100001],b[100001],ma,ans;
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin>>n>>h;
	for (int i=0;i<n;++i) cin>>a[i]>>b[i];
	sort(a,a+n);
	ma=a[n-1];
	sort(b,b+n);
	for (int i=n-1;i>=0;--i)
		if (b[i]>ma && h>0) h-=b[i],++ans;
	if (h>0) ans+=(h+ma-1)/ma;
	cout<<ans;
	return 0;
}