#include <bits/stdc++.h>
using namespace std;
long long n, h, a, b, mx = 0, total = 0, moves = 0;
deque<long long> throws;
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cin >> n >> h;
  for (int i = 0; i < n; i++) {
    cin >> a >> b;
    if (a > mx) {
      mx = a;
    }
    throws.push_back(b);
    sort(throws.begin(), throws.end(), greater<long long>());
  }
  while (total < h) {
    for (auto it = throws.begin(); it != throws.end(); ++it) {
      if (*it >= mx) {
        total += *it;
        moves++;
      }
    }
    if (total >= h) break;
    if ((h - total) % mx != 0) {
      moves += ((h - total) / mx) + 1;
    } else {
      moves += ((h - total) / mx);
    }
    break;
  }
  cout << moves;
  return 0;
}
