#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  for (int i = 0; i < (int)(n); i++) {
    cin >> a[i] >> b[i];
  }
  sort(b.begin(), b.end());
  reverse(b.begin(), b.end());
  sort(a.begin(), a.end());
  reverse(a.begin(), a.end());
  int k;
  for (int i = 0; i < (int)(n); i++) {
    if (a[0] >= b[i]) {
      break;
    }
    k = i;
  }
  int ans = 0;
  for (int i = 0; i < (int)(k + 1); i++) {
    h -= b[i];
    ans++;
    if (h <= 0) {
      cout << ans << endl;
      return 0;
    }
  }
  if (h % a[0] == 0) {
    cout << ans + h / a[0] << endl;
  } else {
    cout << ans + h / a[0] + 1 << endl;
  }
}
