#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
const int MOD = (int)1e9 + 7, INF = (1 << 27);
const ll INFLL = (1LL << 55);
template <typename T>
void dbg(T x) {
  cout << x << "\n";
}
template <typename T, typename U>
static void chmin(T &x, U y) {
  if (y < x) x = y;
}
template <typename T, typename U>
static void chmax(T &x, U y) {
  if (x < y) x = y;
}
int n, h;
vector<int> a, b;
int main() {
  cin.tie(0), ios::sync_with_stdio(0);
  cin >> n >> h;
  a.resize(n);
  b.resize(n);
  for (ll(i) = (0); i < (ll)(n); i++) {
    cin >> a[i] >> b[i];
  }
  int a0 = *max_element(a.begin(), a.end());
  sort(b.rbegin(), b.rend());
  ll ans = 0;
  for (ll(i) = (0); i < (ll)(n); i++) {
    if (a0 <= b[i]) {
      ans++;
      h -= b[i];
    }
  }
  if (h > 0) {
    ans += h / a0;
    ans += !!(h % a0);
  }
  cout << ans << endl;
  return 0;
}
