#include <bits/stdc++.h>
using namespace std;
long long n, h, a, b, mx = 0, total = 0, moves = 0, A = 0;
vector<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;
    throws.push_back(b);
    if (mx < a) mx = a;
    sort(throws.begin(), throws.end(), greater<long long>());
  }
  auto it = throws.begin();
  while (h > 0) {
    if (*it < mx) break;
    h -= (*it);
    moves++;
    ++it;
  }
  if (h > 0) {
    A = (h - total) / mx;
    if ((h - total) % mx != 0) A++;
  }
  cout << moves + A;
  return 0;
}
