#include <bits/stdc++.h>

using namespace std;
typedef long long ll;


int main() {
  int n, h;
  cin >> n >> h;

  vector<int> a(n), b(n);
  int maxa = 0;
  for (int i = 0; i < n; i++) {
    cin >> a[i] >> b[i];
    maxa = max(maxa, a[i]);
  }
  sort(b.begin(), b.end(), greater<int>());

  int ans = 0;
  for (int i = 0; i < n && h > 0 && b[i] > maxa; i++) {
    h -= b[i];
    ans++;
  }
  if (h > 0) ans += (h + maxa - 1) / maxa;
  cout << ans << endl;

  return 0;
}