#include <bits/stdc++.h>

using namespace std;

int main(){
  int N, H;
  cin >> N >> H;
  vector<pair<int, int>> K(N); 
  for(int i=0;i<N;i++){
    cin >> K[i].first >> K[i].second;
  }
  sort(K.begin(), K.end(), [&](auto l, auto r){return l.first > r.first;});
  int ans = (H + K[0].first - 1) / K[0].first;
  for(int i=0, bsum = 0; i < N; i++){
    bsum += K[i].second;
    int tans = i + 1 + (H - bsum + K[i].first - 1) / K[0].first;
    ans = min(ans, tans);
  }
  cout << ans << endl;
}