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#include<iostream>

#define REP(i,n) for(int i=0;i<(n);++i)
#define FOR(i,a,b) for(int i=(a);i<=(b);++i)
#define FORD(i,a,b) for(int i=(a);i>=(b);--i)

using namespace std;

const int MAXN = 500000;

int T[1+MAXN], Q[1+MAXN];
int n, a, res;

int main(void) {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	
	cin >> n;
	REP(i, n+1) T[i] = Q[i] = 0;
	REP(i, n) { cin >> a; T[a]++; }
	FOR(i, 1, n) Q[T[i]]++;
	Q[0] = 0;	
	// FOR(i, 0, n) cout << T[i] << " "; cout << endl;	
	// FOR(i, 0, n) cout << Q[i] << " "; cout << endl;
	
	res = 0;
	int s = 1;
	
	FORD(k, n, 1) while (Q[k] > 0) {
		Q[k]--;
		res++;
		int p = k-1;
		int i = s;
		for(;;) {
			if(Q[i] == 0) {
				i++; s=i;
				if (i > n) break;
			} else {
				Q[i] -= 1;
				if (p >= i) {
					p -= i;
				} else {
					i-=p;
					Q[i]++;
					s=i;
					break;
				}
			}
		}
	}
	
	cout << res << endl;

	return 0;
}