#include <bits/stdc++.h>
using namespace std;
const int inf = 1e9 + 7;
const long long longinf = 1LL << 60;
const int mx = 200010;
const long long mod = 1e9 + 7;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> a(n), b(n);
  for (int i = (int)(0); i < (int)(n); ++i) {
    cin >> a[i] >> b[i];
  }
  sort(a.rbegin(), a.rend());
  sort(b.rbegin(), b.rend());
  int cnt = 0;
  while (h > 0 && b[cnt] > a[0]) {
    h -= b[cnt];
    cnt++;
    if (cnt == n) {
      break;
    }
  }
  int ans = cnt + (h + a[0] - 1) / a[0];
  cout << ans << endl;
  return 0;
}
