#include <bits/stdc++.h>
using namespace std;
const int maxn = 10000 + 1;
int main(int argc, char *argv[]) {
  int n;
  int h;
  scanf("%d%d", &n, &h);
  int maxw = -1;
  int w[maxn], t[maxn];
  for (int i = 1; i <= n; ++i) {
    scanf("%d%d", &w[i], &t[i]);
    if (w[i] > maxw) maxw = w[i];
  }
  sort(t + 1, t + 1 + n);
  int ans = 0;
  for (int i = n; i >= 1; --i) {
    if (t[i] <= maxw) break;
    if (h > 0) {
      h -= t[i];
      ++ans;
    } else
      break;
  }
  if (h > 0) {
    ans += (h - 1) / maxw + 1;
  }
  printf("%d", ans);
  return 0;
}
