#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	ll n,h;
	cin>>n>>h;
	ll a[n],b[n], amax = -1;
	for(int i=0;i<n;i++){
		cin>>a[i]>>b[i];
		amax = max(a[i],amax);
	}
	sort(b,b+n);
	ll ans = 0;
	int i = n-1;
	while(h > 0 && i>=0 && b[i] >= amax){
		h-=b[i];
		++ans;
		--i;
	}
	if(h > 0) ans+= ceil((ld)h/(ld)amax);
	cout<<ans<<"\n";
	return 0;
}