import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) throws Exception {
		BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
		int n = Integer.parseInt(br.readLine());
		String[] sa = br.readLine().split(" ");
		int[] a = new int[n];
		for (int i = 0; i < n; i++) {
			a[i] = Integer.parseInt(sa[i]);
		}
		br.close();

		long[] c = new long[3];
		for (int i = 0; i < n; i++) {
			if (a[i] <= 2) {
				c[a[i]]++;
			}
		}
		c[0] = n - c[1] - c[2];

		long ans = 0;
		ans += c[0] * (c[0] - 1) / 2;
		ans += c[0] * c[1] * 2;
		ans += c[0] * c[2];
		ans += c[1] * (c[1] - 1) / 2 * 2;
		ans += c[1] * c[2] * 3;
		ans += c[2] * (c[2] - 1) / 2;
		System.out.println(ans);
	}
}