#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, h;
  cin >> n >> h;
  vector<int> b(n);
  int a = 0;
  for (int i = 0; i < n; i++) {
    int an;
    cin >> an >> b[i];
    if (an > a) a = an;
  }
  sort(b.begin(), b.end());
  int a_num = h / a;
  a_num += h % a == 0 ? 0 : 1;
  int b_sum = 0;
  int b_num = 0;
  for (int i = 0; i < n; i++) {
    if (b_sum >= h) break;
    if (a >= b[i]) break;
    b_num++;
    b_sum += b[i];
    a_num = (h - b_sum) / a;
    if (h > b_sum) a_num += (h - b_sum) % a == 0 ? 0 : 1;
  }
  printf("%d", a_num + b_num);
  return 0;
}
