#include <bits/stdc++.h>
using namespace std;
string itosm(long long x) {
  if (x == 0) return "0";
  string res = "";
  while (x > 0) {
    res += ((x % 10) + '0');
    x /= 10;
  }
  reverse(res.begin(), res.end());
  return res;
}
long long stoim(string str) {
  long long res = 0;
  int p = 0;
  if (str[0] == '-') p++;
  for (int i = p; i < str.length(); i++) {
    res *= 10;
    res += (str[i] - '0');
  }
  return res;
}
const long long infll = 1e18 + 3;
const int inf = 1009000999;
const long double eps = 1e-7;
const int maxn = 1.5e7 + 1146;
const int baseint = 1000200013;
const long long basell = 1e18 + 3;
const long double PI = acos(-1.0);
const long long mod = 998244353;
long long binpow(long long x, long long st) {
  if (st == 0) return 1;
  if (st & 1) return binpow(x, st - 1) * x % mod;
  long long res = binpow(x, st >> 1);
  return res * res % mod;
}
map<int, int> m;
int cnt[30];
vector<int> p;
void solve() {
  int n;
  cin >> n;
  for (int i = 0; i < n; i++) {
    string a;
    cin >> a;
    for (int j = 0; j < 30; j++) cnt[j] = 0;
    for (char c : a) cnt[c - 'a']++;
    int x = 0;
    for (int j = 0; j < 30; j++)
      if (cnt[j] & 1) x += (1 << j);
    m[x]++;
    p.push_back(x);
  }
  long long ans = 0;
  for (int i = 0; i < n; i++) {
    ans += (m[p[i]] - 1);
    for (int j = 0; j < 30; j++) ans += (m[p[i] ^ (1 << j)]);
  }
  cout << ans / 2;
}
int main() {
  srand(time(0));
  ios_base::sync_with_stdio(0);
  ;
  cin.tie(0);
  cout.tie(0);
  solve();
  return 0;
}
