#include <bits/stdc++.h>
using namespace std;
struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
#define FOR(i, begin, end) for(int i=(begin);i<(end);i++)
#define REP(i, n) FOR(i,0,n)
#define IFOR(i, begin, end) for(int i=(end)-1;i>=(begin);i--)
#define IREP(i, n) IFOR(i,0,n)
#define Sort(v) sort(v.begin(), v.end())
#define Reverse(v) reverse(v.begin(), v.end())
#define all(v) v.begin(),v.end()
#define SZ(v) ((int)v.size())
#define Lower_bound(v, x) distance(v.begin(), lower_bound(v.begin(), v.end(), x))
#define Upper_bound(v, x) distance(v.begin(), upper_bound(v.begin(), v.end(), x))
#define chmax(a, b) a = max(a, b)
#define chmin(a, b) a = min(a, b)
#define bit(n) (1LL<<(n))
#define debug(x) cout << #x << "=" << x << endl;
#define vdebug(v) { cout << #v << "=" << endl; REP(i_debug, v.size()){ cout << v[i_debug] << ","; } cout << endl; }
#define mdebug(m) { cout << #m << "=" << endl; REP(i_debug, m.size()){ REP(j_debug, m[i_debug].size()){ cout << m[i_debug][j_debug] << ","; } cout << endl;} }
#define pb push_back
#define fi first
#define se second
//#define int long long
//#define INF 1000000000000000000
template<typename T> istream &operator>>(istream &is, vector<T> &v){ for (auto &x : v) is >> x; return is; }
template<typename T> ostream &operator<<(ostream &os, vector<T> &v){ for(int i = 0; i < v.size(); i++) { cout << v[i]; if(i != v.size() - 1) cout << endl; }; return os; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, pair<T1, T2> p){ cout << '(' << p.first << ',' << p.second << ')'; return os; }
template<typename T> void Out(T x) { cout << x << endl; }
template<typename T1, typename T2> void chOut(bool f, T1 y, T2 n) { if(f) Out(y); else Out(n); }

using vec = vector<int>;
using mat = vector<vec>;
using Pii = pair<int, int>;
using v_bool = vector<bool>;
using v_Pii = vector<Pii>;

//int dx[4] = {1,0,-1,0};
//int dy[4] = {0,1,0,-1};
//char d[4] = {'D','R','U','L'};

const int mod = 1000000007;
//const int mod = 998244353;

struct Trie{

    static const int N_alphabet = 26;
    static const char begin_alphabet = 'a';
    using data_type = int;
    static const data_type not_exist = 0;

    Trie *next[N_alphabet];
    vector<data_type> val;

    Trie(){
        fill(next, next + N_alphabet, (Trie *)0);
        val = vec(26, 0);
    }

    // Sに対してval=vにupdate
    void insert(string &S, vec &num, int i = 0){
        if(i < S.size()){
            REP(j, 26) if(num[j] > 0){
                val[j]++;
            }

            num[S[i] - begin_alphabet]--;
            if(this->next[S[i] - begin_alphabet] == NULL)
                this->next[S[i] - begin_alphabet] = new Trie();
            this->next[S[i] - begin_alphabet]->insert(S, num, i + 1);    
        }
    }

    // Sのvalを求める、なければnot_existを返す
    data_type find(string &S, int i = 0){
        if(i == S.size() - 1) return this->val[S[i] - 'a'];
        if(this->next[S[i] - begin_alphabet] == NULL) return not_exist;
        return this->next[S[i] - begin_alphabet]->find(S, i + 1);
    }
};

signed main(){

    int N; cin >> N;
    vector<string> S(N); cin >> S;

    v_Pii p(N);
    REP(i, N) p[i] = Pii(SZ(S[i]), i);
    Sort(p); Reverse(p);

    Trie T;

    long long ans = 0;
    REP(i, N){
        int i0 = p[i].se;
        Reverse(S[i0]);
        ans += T.find(S[i0]);

        vec num(26);
        for(char c: S[i0]) num[c - 'a']++;
        T.insert(S[i0], num);
    }
    Out(ans);

    return 0;
}


Measured memory_bytes: 347736