#include<stdio.h>
#include<math.h>
#include<string.h>
#include<stack>
#include<set>
#include<queue>
#include<vector>
#include<iostream>
#include<algorithm>
#define MAXN 1010000
#define LL long long
#define ll __int64
#define INF 0xfffffff
#define mem(x) memset(x,0,sizeof(x))
#define PI acos(-1)
#define eps 1e-8
using namespace std;
ll gcd(ll a,ll b){return b?gcd(b,a%b):a;}
ll lcm(ll a,ll b){return a/gcd(a,b)*b;}
ll powmod(ll a,ll b,ll MOD){ll ans=1;while(b){if(b%2)ans=ans*a%MOD;a=a*a%MOD;b/=2;}return ans;}
double dpow(double a,ll b){double ans=1.0;while(b){if(b%2)ans=ans*a;a=a*a;b/=2;}return ans;}
//head
int a[110],v[110];
int main()
{
    int n,i,j;
    while(scanf("%d",&n)!=EOF)
    {
        for(i=0;i<n;i++)
            scanf("%d",&a[i]);
        sort(a,a+n); int ans=0;mem(v);
        for(i=0;i<n;i++)
        {
            if(v[i])
                continue;
            int num=1;
            for(j=i+1;j<n;j++)
            {
                if(a[j]>=num&&!v[j])
                {
                    num++;
                    v[j]=1;
                }
            }
            ans++;
        }
        printf("%d\n",ans);
    }
    return 0;
}