#include <bits/stdc++.h>
using namespace std;
int k[100011], t[100011];
int main() {
  int n, m, maxk = 0;
  cin >> n >> m;
  for (int i = 0; i < n; i++) {
    cin >> k[i] >> t[i];
    maxk = max(maxk, k[i]);
  }
  int ans = (m - 1) / maxk + 1;
  sort(t, t + n);
  for (int i = 0; i < n; i++) {
    m -= t[i];
    if (m <= 0)
      ans = i + 1;
    else
      ans = min(ans, (m - 1) / maxk + i + 1 + 1);
  }
  cout << ans << endl;
}
