#include <bits/stdc++.h>
using namespace std;

struct cp
{
    bool operator()(const pair<int,int>x, const pair<int,int>y) const
    {
        if(x.second!=y.second) return x.second>y.second;
        else return x.first>=y.first;
    }
};

int main()
{
    cin.tie(NULL);
    cout.tie(NULL);
    ios_base::sync_with_stdio(NULL);
    int x,pom,pp;
    cin >> x;
    set<pair<int,int>,cp> set1;
    set<pair<int,int>,cp>::iterator it;
    int tab[x+1]={0};
    for (int i=0; i<x; i++)
    {
        cin >> pom;
        tab[pom]++;
    }
    for (int i=0; i<x; i++) if (tab[i]!=0) set1.insert({i,tab[i]});
    int ile=0;
    while (set1.size())
    {
        ile++;
        pom=(*set1.begin()).second;
        set1.erase(set1.begin());
        pp=0;
        while (pp<pom&&set1.size())
        {
            it=set1.end();
            it--;
            pp+=(*it).second; 
            if (pp>=pom) break;
            set1.erase(it);
        }
    }
    cout << ile;
    return 0;
}