#include <bits/stdc++.h>
#pragma GCC optimize("O3")
using namespace std;
const long long mod = 1e9 + 7;
int n, h, a[100001], b[100001], ans, d;
int32_t main() {
  ios_base ::sync_with_stdio(0);
  cin.tie();
  cout.tie();
  cin >> n >> h;
  for (int i = 1; i <= n; i++) cin >> a[i] >> b[i];
  sort(a + 1, a + n + 1);
  sort(b + 1, b + n + 1);
  int k = n;
  while (d < h && k != 0) {
    ans++, d += b[k];
    k--;
  }
  if (d >= h)
    cout << ans;
  else {
    ans += ceil(double((h - d) / a[n]));
    cout << ans;
  }
}
