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