#include <bits/stdc++.h>
using namespace std;
int a[100005], b[100005];
int main() {
  int n, m;
  cin >> n >> m;
  for (int i = 0; i < n; i++) cin >> a[i] >> b[i];
  sort(a, a + n);
  sort(b, b + n);
  int num = 0;
  int ans = 0;
  for (int i = 0; i < n; i++) {
    if (b[i] > a[n - 1]) {
      num = i;
      break;
    }
  }
  for (int i = n - 1; i >= num; i--) {
    ans++;
    m -= b[i];
    if (m <= 0) {
      cout << ans;
      return 0;
    }
  }
  if (m % a[n - 1] == 0)
    cout << ans + (m / a[n - 1]);
  else
    cout << ans + (m / a[n - 1] + 1);
  return 0;
}
