#include<bits/stdc++.h>
using namespace std;
using ll=long long;


int main(){
  ll n,h;
  cin >> n >> h;
  vector<ll> a(n),b(n);
  ll ma=0;
  for(ll i=0;i<n;++i){
    cin >> a[i] >> b[i];
    ma=max(ma,a[i]);
  }
  sort(b.rbegin(),b.rend());
  int j=0;
  int kazu=b.size();
  ll ans=0;
  while(h>0){
    if(kazu>0 && ma<b[j]){
      h=h-b[j];
      j++;
      kazu--;
      ans++;
    }else{
      h=h-ma;
      ans++;
    }
  }
  cout << ans << endl;
  return 0;
}
