#include <iostream>
#include <vector>
#include <string>
#include <sstream>

using namespace std;

class ColorfulRabbits {
public:
	int getMinimum(vector <int> replies) {
		static int cnt[1000001];
		memset(cnt, 0, sizeof(cnt));
		for(int i=0;i<replies.size();i++)
			cnt[replies[i]]++;
		int res = 0;
		for(int i=0;i<=1000000;i++)
			res += (cnt[i]+i)/(i+1)*(i+1);
		return res;
	}
};