#include <bits/stdc++.h>
#define int long long
using namespace std;

signed main(){
	int N,H; cin>>N>>H;
	vector<int> a(N);
	vector<int> b(N);
	for(int i=0;i<N;i++)cin>>a[i]>>b[i];
	sort(b.begin(),b.end());
	reverse(b.begin(),b.end());
	sort(a.begin(),a.end());
	reverse(a.begin(),a.end());
	int j=0; int ans=0;
	while(b[j]>a[0] && j<N && H>0){
		H-=b[j]; j++; ans++;
	}
	if(H>0){
		double t,h,p;h=H;p=a[0]; t=h/p; ans+=ceil(t);
	}
	cout<<ans<<endl;
}
