#include <bits/stdc++.h>
using namespace std;

#define fu(i,a,b) for(int i = a; i <= b; i++)
#define fd(i,a,b) for(int i = a; i >= b; i--)
#define pb push_back
#define int long long
#define task "test"
#define pii pair<int,int>
const int MAXN = 1e5 + 1, MAXNN = 7e7 + 1, INF = 1e18, MOD = 1e9 + 7;
int a[MAXN];
int mp[MAXNN];

signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    if(fopen(task ".inp","r")) {
        freopen(task ".inp","r",stdin);
        //freopen(task ".out","w",stdout);
    }
    int n; cin >> n;
    int res = 0;
    fu(i,1,n) {
        string s; cin >> s;
        vector<int> c(30);
        for(char x: s) c[x - 'a'] = (c[x - 'a']  + 1);
        int cur = 1;
        int m = 0;
        fu(cx,0,25) if(c[cx] & 1) m |= (1 << cx);

        res += mp[m];
        fu(b,0,25) res += mp[(m ^ (1 << b))];
        mp[m]++;

    }
    //fu(i,1,n) cout << a[i] << "\n";
    cout << res;

}


/*
1 2 3 4 5 6
1 2 3 2 2 5 2 3

*/