#include <bits/stdc++.h>
using namespace std;
int arr_wield[100001], arr_throw[100001];
bool mycompare(const int &a, const int &b) { return a > b; }
int main() {
  int n, h = 0, i, count = 0, ans = 0, pos_w = 0, pos_t = 0;
  scanf("%d %d", &n, &h);
  for (i = 0; i < n; i++) {
    scanf("%d %d", &arr_wield[i], &arr_throw[i]);
  }
  sort(arr_wield, arr_wield + n, mycompare);
  sort(arr_throw, arr_throw + n, mycompare);
  while (h > 0) {
    if (arr_throw[pos_t] > arr_wield[0]) {
      h -= arr_throw[pos_t++];
      ans++;
    } else {
      ans += h / arr_wield[0];
      ans += h % arr_wield[0] == 0 ? 0 : 1;
    }
  }
  printf("%d", ans);
  return 0;
}
