#pragma region template 2.4
#include <bits/stdc++.h>
using namespace std;
template <typename T>
using pq_asc = priority_queue<T, vector<T>, greater<T>>;
typedef long long ll;
typedef vector<ll> vi;
typedef vector<vi> vvi;
typedef pair<ll, ll> ii;
typedef vector<ii> vii;
typedef vector<string> vs;
#define REP(i, n) for (ll i = 0; i < (n); ++i)
#define REP1(i, n) for (ll i = 1; i <= (n); ++i)
#define FOR(i, a) for (auto &i : a)
#define CH(f, x, y) x = f(x, y)
#define IN(T, x) \
    T x;         \
    cin >> x;
#define AIN(T, a, n) \
    vector<T> a(n);  \
    FOR(i, a)        \
    cin >> i;
#define A2IN(T1, a, T2, b, n) \
    vector<T1> a(n);          \
    vector<T2> b(n);          \
    REP(i, n)                 \
    cin >> a[i] >> b[i];
#define OUT(x) cout << (x) << endl;
#define FOUT(x) cout << fixed << setprecision(15) << (x) << endl;
#define ALL(a) (a).begin(), (a).end()
#define SORT(a) sort(ALL(a))
#define RSORT(a) \
    SORT(a);     \
    reverse(ALL(a))
#define DUMP(x) cout << #x << " = " << (x) << endl;
#define DUMPA(a)          \
    cout << #a << " = {"; \
    JOUT(ALL(a), ", ", cout) << "}" << endl;

template <typename T>
ostream &JOUT(T s, T e, string sep = " ", ostream &os = cout)
{
    if (s != e)
    {
        os << *s;
        ++s;
    }
    while (s != e)
    {
        os << sep << *s;
        ++s;
    }
    return os;
}

ostream &YES(bool cond, string yes = "Yes", string no = "No", ostream &os = cout)
{
    if (cond)
    {
        os << yes << endl;
    }
    else
    {
        os << no << endl;
    }
    return os;
}

template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p)
{
    os << '(' << p.first << ", " << p.second << ')';
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v)
{
    os << '[';
    JOUT(ALL(v), ", ", os) << ']';
    return os;
}

const ll INF = 1e18;
const ll MOD = 1e9 + 7;
#pragma endregion template
#pragma region rollinghash 1.0
const ll RH_BASE[2] = {1007, 2009};
const ll RH_MOD[2] = {1000000007, 1000000009};

struct rollinghash
{
    vvi h;
    vvi p;

    rollinghash() {}

    rollinghash(const string &s)
    {
        ll n = s.size();
        h.assign(2, {});
        p.assign(2, {});
        REP(k, 2)
        {
            h[k].assign(n + 1, 0);
            p[k].assign(n + 1, 1);
            REP(i, n)
            {
                h[k][i + 1] = (RH_BASE[k] * h[k][i] + s[i]) % RH_MOD[k];
                p[k][i + 1] = (RH_BASE[k] * p[k][i]) % RH_MOD[k];
            }
        }
    }

    ii hash(ll i, ll j)
    {
        ll h0 = (h[0][j] - h[0][i] * p[0][j - i]) % RH_MOD[0];
        ll h1 = (h[1][j] - h[1][i] * p[1][j - i]) % RH_MOD[1];
        return {(h0 + RH_MOD[0]) % RH_MOD[0], (h1 + RH_MOD[1]) % RH_MOD[1]};
    }
};
#pragma endregion rollinghash

int main()
{
    IN(ll, N);
    AIN(string, S, N);
    sort(ALL(S), [&](string x, string y) {
        if (x.size() != y.size())
        {
            return x.size() < y.size();
        }
        return x < y;
    });
    vector<rollinghash> R;
    vvi P;
    FOR(s, S)
    {
        R.push_back(rollinghash(s));
        vi p(26, INF);
        for (ll j = s.size() - 1; j >= 0; --j)
        {
            p[s[j] - 'a'] = j;
        }
        P.push_back(p);
    }
    ll ans = 0;
    map<ii, vi> dp;
    REP(i, N)
    {
        ll len_i = S[i].size();
        if (i == 0 or len_i > S[i - 1].size())
        {
            for (ll j = i + 1; j < N; ++j)
            {
                ll len_j = S[j].size();
                if (len_j == len_i)
                {
                    continue;
                }
                auto h = len_i == 1 ? ii(0LL, 0LL) : R[j].hash(len_j - (len_i - 1), len_j);
                if (dp.find(h) == dp.end())
                {
                    dp[h] = vi(26, 0);
                }
                REP(k, 26)
                {
                    dp[h][k] += P[j][k] < len_j - (len_i - 1);
                }
            }
        }
        auto h = len_i == 1 ? ii(0LL, 0LL) : R[i].hash(1, S[i].size());
        if (dp.count(h))
        {
            ans += dp[h][S[i][0] - 'a'];
        }
    }
    OUT(ans);
}

Measured memory_bytes: 329832