#include <stdio.h>

int main () {
  int n = 0;
  int a = 0;
  
  int res = 0;
  
  long long pow[8][8] = {};
  long long cnt[8] = {};
  
  long long ans = 0LL;
  
  res = scanf("%d", &n);
  for (int i = 0; i < n; i++) {
    res = scanf("%d", &a);
    cnt[a-1] += 1LL;
  }
  
  for (int i = 0; i < 8; i++) {
    pow[i][0] = (long long) (i+1);
    for (int j = 1; j < 8; j++) {
      pow[i][j] = ((long long)(i+1))*pow[i][j-1];
    }
  }
  
  for (int i = 0; i < 8; i++) {
    for (int j = 0; j < 8; j++) {
      ans += pow[i][j]*cnt[i]*cnt[j];
    }
  }
  
  printf("%lld\n", ans);
  return 0;
}