#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = 1e9;
const int MOD = 1e9 + 7;
int dx[] = {1, 0, -1, 0, 1, -1, -1, 1};
int dy[] = {0, 1, 0, -1, 1, 1, -1, -1};
int main() {
  int N, H;
  cin >> N >> H;
  int a[N], b[N];
  for (int i = 0; i < N; i++) cin >> a[i] >> b[i];
  vector<P> p(N);
  for (int i = 0; i < N; i++) p[i] = P(a[i], -b[i]);
  sort(p.begin(), p.end());
  vector<int> v;
  for (int i = N - 2; i >= 0; i--) v.push_back(-p[i].second);
  sort(v.begin(), v.end());
  int ans = 0;
  for (int i = v.size() - 1; i >= 0; i--) {
    if (p[N - 1].first > v[i]) break;
    H -= v[i];
    ans++;
    if (H <= 0) break;
  }
  if (H - (-p[N - 1].second) > 0) {
    H -= -p[N - 1].second;
    ans += (H + p[N - 1].first - 1) / p[N - 1].first;
  }
  cout << ans + 1 << endl;
  return 0;
}
