#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 < n; i++) {
    cin >> a[i] >> b[i];
  }
  sort(b.begin(), b.end());
  int a_max = a[0];
  for (int i = 1; i < n; i++) {
    if (a_max < a[i]) {
      a_max = a[i];
    }
  }
  if (a_max == b[n - 1]) {
    cout << (h + a_max - 1) / a_max << endl;
    return 0;
  }
  int p = 0;
  while (a_max > b[p]) {
    p++;
  }
  int ans = 0;
  for (int i = n - 1; i >= p && h > 0; i--) {
    h -= b[i];
    ans++;
  }
  ans += (h + a_max - 1) / a_max;
  cout << ans << endl;
  return 0;
}
