#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 10;
int a[N], b[N];
int main() {
  int n, h, maxn = 0, cnt = 0;
  cin >> n >> h;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    maxn = max(maxn, a[i]);
  }
  sort(b, b + n);
  for (int i = n - 1; i >= 0; i--) {
    if (b[i] < maxn) break;
    h -= b[i];
    cnt++;
    if (h < 0) break;
  }
  if (h > 0) {
    if (h % maxn == 0)
      cout << cnt + h / maxn << endl;
    else
      cout << cnt + 1 + h / maxn << endl;
  } else
    cout << cnt << endl;
  return 0;
}
