1 #include <iostream>
 2 #include <cstdio>
 3 #include <cstdlib>
 4 #include <cstring>
 5 #include <algorithm>
 6 using namespace std;
 7 
 8 const int maxn = 100 + 10;
 9 int a[maxn], vis[maxn];
10 
11 int main()
12 {
13     int i, n;
14     while (scanf("%d", &n) != EOF)
15     {
16         for (i = 0; i < n; i++)
17             scanf("%d", &a[i]);
18         memset(vis ,0, sizeof(vis));
19         sort(a, a+n);
20         int ans = 0;
21         int tmp, tol = n;
22         while (tol)
23         {
24             tmp = 0;
25             for (i = 0; i < n; i++)
26             {
27                 if (tmp <= a[i] && !vis[i])
28                 {
29                     vis[i] = 1;
30                     tmp++;    // 下一层需要的最小strength
31                     tol--;   // box用了一个
32                 }
33             }
34             ans++;   // 一个pile建立
35         }
36         printf("%d\n", ans);
37     }
38     return 0;
39 }