#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  int a[n], b[n];
  for (int i = 0; i < (n); ++i) cin >> a[i] >> b[i];
  sort(a, a + n, greater<int>());
  sort(b, b + n, greater<int>());
  int ans = 0;
  int i = 0;
  while (b[i] > a[0]) {
    h -= b[i];
    ++ans;
    ++i;
    if (h <= 0 || i == n) break;
  }
  ans += h / a[0];
  if (h % a[0] != 0) ++ans;
  cout << ans << endl;
  return 0;
}
