#include <bits/stdc++.h>
using namespace std;
int main() {
  int long long n, h;
  int long long mi = 10000000000;
  cin >> n >> h;
  vector<int long long> a(n);
  vector<int long long> b(n);
  for (int i = 0; i < n; i++) {
    int long long x, y;
    cin >> x >> y;
    a.push_back(x);
    b.push_back(y);
  }
  vector<int long long> bb(n);
  sort(a.rbegin(), a.rend());
  sort(b.rbegin(), b.rend());
  int long long ans = 0;
  int long long nokori = h;
  for (int i = 0; i < n; i++) {
    if (b[i] > a[0]) {
      ans++;
      nokori -= b[i];
      if (nokori < 0) {
        cout << ans << endl;
        return 0;
      }
    }
  }
  ans += nokori / a[0];
  if (nokori % a[0] != 0) ans++;
  cout << ans << endl;
  return 0;
}
