#include <algorithm>
#include <array>
#include <bitset>
#include <cassert>
#include <chrono>
#include <cmath>
#include <complex>
#include <cstdint>
#include <cstring>
#include <ctime>
#include <deque>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <unordered_map>
#include <unordered_set>
template <int mod>
struct ModInt {
  int x;
  ModInt() : x(0) {}
  ModInt(long long y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}
  ModInt &operator+=(const ModInt &p) {
    if ((x += p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt &operator-=(const ModInt &p) {
    if ((x += mod - p.x) >= mod) x -= mod;
    return *this;
  }
  ModInt &operator*=(const ModInt &p) {
    x = (int)(1LL * x * p.x % mod);
    return *this;
  }
  ModInt &operator/=(const ModInt &p) {
    *this *= p.inverse();
    return *this;
  }
  ModInt &operator^=(long long p) {  // quick_pow here:3
    ModInt res = 1;
    for (; p; p >>= 1) {
      if (p & 1) res *= *this;
      *this *= *this;
    }
    return *this = res;
  }
  ModInt operator-() const { return ModInt(-x); }
  ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }
  ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }
  ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }
  ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }
  ModInt operator^(long long p) const { return ModInt(*this) ^= p; }
  bool operator==(const ModInt &p) const { return x == p.x; }
  bool operator!=(const ModInt &p) const { return x != p.x; }
  explicit operator int() const { return x; }  // added by QCFium
  ModInt operator=(const int p) {
    x = p;
    return ModInt(*this);
  }  // added by QCFium
  ModInt inverse() const {
    int a = x, b = mod, u = 1, v = 0, t;
    while (b > 0) {
      t = a / b;
      a -= t * b;
      std::swap(a, b);
      u -= t * v;
      std::swap(u, v);
    }
    return ModInt(u);
  }
  friend std::ostream &operator<<(std::ostream &os, const ModInt<mod> &p) {
    return os << p.x;
  }
  friend std::istream &operator>>(std::istream &is, ModInt<mod> &a) {
    long long x;
    is >> x;
    a = ModInt<mod>(x);
    return (is);
  }
};

long long mod_pow(long long x, int n, int p) {
  long long ret = 1;
  while (n) {
    /*
  ∧,,,∧
(  ̳• · • ̳)
/    づ♡ I love you
    */
    if (n & 1) (ret *= x) %= p;
    (x *= x) %= p;
    n >>= 1;
  }
  return ret;
}
// using mint = ModInt<1000000007>;
using mint = ModInt<998244353>;

// m, n , sum
std::pair<std::vector<long long>, std::vector<int>> get_prime_factor_with_kinds(
    long long n) {
  std::vector<long long> prime_factors;
  std::vector<int> cnt;  // number of i_th factor
  for (long long i = 2; i <= sqrt(n); i++) {
    if (n % i == 0) {
      prime_factors.push_back(i);
      cnt.push_back(0);
      while (n % i == 0) n /= i, cnt[(int)prime_factors.size() - 1]++;
    }
  }
  if (n > 1) prime_factors.push_back(n), cnt.push_back(1);
  assert(prime_factors.size() == cnt.size());
  return {prime_factors, cnt};
}
void solve() {
  int n;
  std::cin >> n;
  std::vector<int> cnt(9, 0);
  std::vector<int> a(n);
  for (int &x : a) {
    std::cin >> x;
    cnt[x] += 1;
  }
  long long ans = 0;
  std::vector<std::vector<int>> pre(9, std::vector<int>(9, 0));
  for (int i = 1; i <= 8; i++) {
    for (int j = 1; j <= 8; j++) {
      pre[i][j] = pow(i, j);
    }
  }
  for (int i = 1; i <= 8; i++) {
    for (int j = 1; j <= 8; j++) {
      ans += 1LL * cnt[i] * cnt[j] * pre[i][j];
    }
  }
  std::cout << ans << '\n';
}

int main() {
  std::ios::sync_with_stdio(false);
  std::cin.tie(nullptr);

  int t = 1;
  // std::cout << std::boolalpha;
  // std::cin >> t;
  while (t--) solve();
  return 0;
}