#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int n, h;
  cin >> n >> h;
  int mx = 0;
  vector<int> A(n);
  for (int i = 0; i < n; i++) {
    int x;
    cin >> x >> A[i];
    mx = max(mx, x);
  }
  sort(A.begin(), A.end(), greater<int>());
  int res = 0;
  int i = 0;
  while (true) {
    if (h <= 0 || A[i] < mx || i >= A.size()) {
      break;
    }
    h -= A[i];
    i++;
    res++;
  }
  res += (h / mx) + (h % mx > 0 ? 1 : 0);
  cout << res;
  return 0;
}
