#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 x = -1;
  ll pos = 0;
  ll pp = 1e10;
  pair<int, int> p;
  for (int i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
    if (a[i] > x) {
      pos = i;
      x = a[i];
    } else if (a[i] == x) {
      if (b[i] < pp) {
        pp = b[i];
        pos = i;
        x = a[i];
      }
    }
  }
  if (N == 1) {
    if (H - b[0] <= 0) {
      cout << 1 << endl;
    } else {
      cout << (H) / a[0] << endl;
    }
    return 0;
  }
  p = make_pair(a[pos], b[pos]);
  b.erase(b.begin() + pos);
  sort(b.begin(), b.end(), greater<int>());
  sort(a.begin(), a.end(), greater<int>());
  int cnt = 0;
  int z = 0;
  while (H > 0) {
    if (H - p.second <= 0) {
      cnt++;
      break;
    }
    if (cnt <= N - 1 && b[z] > p.first) {
      H -= b[z];
      z++;
      cnt++;
    } else {
      ll t = ceil((double)(H - p.second) / p.first);
      cnt += t;
      H -= t;
      cnt++;
      break;
    }
  }
  cout << cnt << endl;
  return 0;
}
