#include <bits/stdc++.h>
using namespace std;
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return 1;
  }
  return 0;
}
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  long long N, H;
  cin >> N >> H;
  long long a[N], b[N];
  long long maxv = 0, bmax = 0, cnt = 0, ans = 0;
  for (long long i = 0; i < N; i++) {
    cin >> a[i] >> b[i];
    maxv = max(maxv, a[i]);
    if (maxv >= H) {
      cout << 1 << endl;
      return 0;
    }
  }
  for (long long i = 0; i < N; i++) {
    if (maxv <= b[i]) {
      cnt++;
      bmax += b[i];
      if (bmax >= H) {
        cout << cnt << endl;
        return 0;
      }
    }
  }
  do {
    ans++;
    H -= maxv;
  } while (H > bmax);
  cout << ans + cnt << endl;
}
