#include <bits/stdc++.h>
using namespace std;
int main() {
  long int N, H, non, td, c;
  vector<long int> a, b, is;
  cin >> N >> H;
  a = vector<long int>(N, 0);
  b = vector<long int>(N, 0);
  is = vector<long int>(N, 0);
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
  }
  sort(a.begin(), a.end());
  sort(b.begin(), b.end());
  non = -1;
  td = 0;
  c = 0;
  for (int i = N - 1; i >= 0; i--) {
    if (a[N - 1] > b[i]) {
      non = i;
      break;
    } else {
      td += b[i];
      c++;
    }
  }
  int ac = 0;
  if (td > H) {
    int ct = 0;
    long int dmg = 0;
    for (int i = N - 1; i > non; i--) {
      dmg += b[i];
      ct++;
      if (dmg > H) {
        cout << ct << endl;
        return 0;
      }
    }
  } else {
    H -= td;
    ac = H / a[N - 1];
    if (H % a[N - 1] == 0) {
      cout << (ac + c) << endl;
    } else {
      cout << (ac + 1 + c) << endl;
    }
  }
  return 0;
}
