#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int num, h, i, a, maxa = 0, ans = 0;
  cin >> num >> h;
  vector<int> b(num);
  for (i = 0; i < num; i++) {
    scanf("%d%d", &a, &b[i]);
    maxa = max(maxa, a);
  }
  sort(b.begin(), b.end(), greater<int>());
  for (i = 0; i < num; i++) {
    if (maxa > b[i] || h < 0) break;
    h -= b[i];
    ans++;
  }
  if (h > 0) {
    ans += h / maxa;
    if (h % maxa) ans++;
  }
  printf("%d\n", ans);
  return 0;
}
