#include <algorithm>
#include <array>
#include <cassert>
#include <climits>
#include <cmath>
#include <cstdio>
#include <cstring>
#include <deque>
#include <functional>
#include <iomanip>
#include <iostream>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <stack>
#include <string>
#include <vector>
using namespace std;
typedef long long ll;
#define REP(i,n) for(ll i = 0; i < (ll)(n); ++i)
#define FOR(i,a,b) for(ll i = (a); i < (ll)(b); ++i)
#define ALL(c) (c).begin(), (c).end()
#define SIZE(v) ((int)v.size())
template<class T> inline bool chmin(T& a, T b) {
    if (a > b) {
        a = b; return true;
    }
    return false;
}
template<class T> inline bool chmax(T& a, T b) {
    if (a < b) {
        a = b; return true;
    }
    return false;
}
template<int MOD> struct Fp {
    ll val;
    constexpr Fp(ll v = 0) noexcept : val(v % MOD) {
        if (val < 0) val += MOD;
    }
    constexpr int getmod() { return MOD; }
    constexpr Fp operator - () const noexcept {
        return val ? MOD - val : 0;
    }
    constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; }
    constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; }
    constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; }
    constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; }
    constexpr Fp& operator += (const Fp& r) noexcept {
        val += r.val;
        if (val >= MOD) val -= MOD;
        return *this;
    }
    constexpr Fp& operator -= (const Fp& r) noexcept {
        val -= r.val;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr Fp& operator *= (const Fp& r) noexcept {
        val = val * r.val % MOD;
        return *this;
    }
    constexpr Fp& operator /= (const Fp& r) noexcept {
        ll a = r.val, b = MOD, u = 1, v = 0;
        while (b) {
            ll t = a / b;
            a -= t * b; swap(a, b);
            u -= t * v; swap(u, v);
        }
        val = val * u % MOD;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr bool operator == (const Fp& r) const noexcept {
        return this->val == r.val;
    }
    constexpr bool operator != (const Fp& r) const noexcept {
        return this->val != r.val;
    }
    friend constexpr ostream& operator << (ostream &os, const Fp<MOD>& x) noexcept {
        return os << x.val;
    }
    friend constexpr Fp<MOD> modpow(const Fp<MOD> &a, ll n) noexcept {
        if (n == 0) return 1;
        auto t = modpow(a, n / 2);
        t = t * t;
        if (n & 1) t = t * a;
        return t;
    }
};
constexpr ll MOD = 1e9 + 7;
using mint = Fp<MOD>;

#define pb push_back
#define mp make_pair
#define mt make_tuple

ll solve_fast(int N, vector<string> Ss) {
    map<string, vector<char>> counter;

    map<int, set<string>> srev_set_with_len;

    set<string> srev_set;
    for(auto s: Ss) {
        reverse(ALL(s));
        srev_set.insert(s);
        srev_set_with_len[SIZE(s)].insert(s);
    }

    ll ans = 0;
    for(auto s: Ss){
        // cout << "s: " << s << endl;
        if (SIZE(s) == 1) continue;
        set<char> cnt_set;

        REP(i, 2) {
            cnt_set.insert(s[i]);
        }
        int i = 2;

        string s_rev = s;
        reverse(ALL(s_rev));
        s_rev = s_rev.substr(0, SIZE(s_rev) - 2);

        while(1) {
            int tmp_size = SIZE(s_rev) + 1;
            if (SIZE(srev_set_with_len[tmp_size]) != 0) {
                for(auto ch: cnt_set) {
                    if (srev_set_with_len[tmp_size].count(s_rev + ch)) {
                        ans += 1;
                    }
                }
            }

            if (i == SIZE(s)) break;
            cnt_set.insert(s[i]);
            i += 1;
            s_rev.pop_back();
            // cout << "i = " << i << ", size(cntset) = " << SIZE(cnt_set) << endl;
        }
    }
    return ans;

    // ll ans = 0;
    // for(auto s: Ss) {
    //     string subs = s.substr(1);
    //     // cout << "subs = " << subs << endl;
    //     if (!counter.count(subs)) continue;
    //     auto& ctr = counter[subs];
    //     auto& val = ctr[s[0] - 'a'];
    //     // cout << s << ", " << int(val) << endl;
    //     ans += val;
    // }
    // return ans;
}


int main(void)
{
    ios::sync_with_stdio(false);
    cin.tie(0);
    // while(1){
    //     int N = 10;
    //     vector<string> Ss(N);
    //     REP(n, N) {
    //         string s = "";
    //         REP(i, 1 + rand() % 5) {
    //             s += 'a' + rand() % 26;
    //         }
    //         Ss[n] = s;
    //     }
    //     cout << solve_fast(N, Ss) << endl;
    // }


    int N;
    cin >> N;

    vector<string> Ss(N);
    REP(n, N) cin >> Ss[n];

    auto mine = solve_fast(N, Ss);
    cout << mine << endl;

    return 0;
}


Measured memory_bytes: 101248