#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n, h;
  cin >> n >> h;
  priority_queue<int> a, b;
  int c, d, ans = 0;
  for (int i = 0; i < n; i++) {
    cin >> c >> d;
    a.push(c);
    b.push(d);
  }
  c = a.top();
  while (h >= 0 && !b.empty() && b.top() > c) {
    h -= b.top();
    ans++;
    b.pop();
  }
  if (h > 0) {
    ans += h / c;
  }
  if (h % c != 0 && h >= 0) ans++;
  cout << ans << endl;
  return 0;
}
