#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 5;
pair<int, int> p[N];
bool cmp(pair<int, int> &a, pair<int, int> &b) {
  if (a.first == b.first) return a.second < b.second;
  return a.first > b.first;
}
int main() {
  int n, h;
  cin >> n >> h;
  for (int i = 0; i < n; ++i) scanf("%d %d", &p[i].first, &p[i].second);
  sort(p, p + n, cmp);
  int res = 0;
  for (int i = 1; i < n; ++i) {
    if (p[0].second >= h) {
      res++;
      h = 0;
      break;
    }
    if (p[i].second >= p[0].first) {
      h -= p[i].second;
      res++;
    }
    if (h <= 0) break;
  }
  if (h > 0) {
    h -= p[0].second;
    res++;
    if (h > 0) res += (h + p[0].first - 1) / p[0].first;
  }
  printf("%d\n", res);
}
