#include <bits/stdc++.h>
#define int long long
#define ll long long
using ull = unsigned long long;
using namespace std;
#define dump(x)                             \
    if (dbg) {                              \
        cerr << #x << " = " << (x) << endl; \
    }
#define overload4(_1, _2, _3, _4, name, ...) name
#define FOR1(n) for (ll i = 0; i < (n); ++i)
#define FOR2(i, n) for (ll i = 0; i < (n); ++i)
#define FOR3(i, a, b) for (ll i = (a); i < (b); ++i)
#define FOR4(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define FOR(...) overload4(__VA_ARGS__, FOR4, FOR3, FOR2, FOR1)(__VA_ARGS__)
#define FORR(i, a, b) for (int i = (a); i <= (b); ++i)
#define bit(n, k) ((n >> k) & 1) /*nのk bit目*/
namespace mydef {
const int INF = 1ll << 60;
const int MOD = 1e9 + 7;
template <class T>
bool chmin(T& a, const T& b) {
    if (a > b) {
        a = b;
        return 1;
    } else
        return 0;
}
template <class T>
bool chmax(T& a, const T& b) {
    if (a < b) {
        a = b;
        return 1;
    } else
        return 0;
}
void Yes(bool flag = true) {
    if (flag)
        cout << "Yes" << endl;
    else
        cout << "No" << endl;
}
void No(bool flag = true) {
    Yes(!flag);
}
void YES(bool flag = true) {
    if (flag)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
}
void NO(bool flag = true) {
    YES(!flag);
}
template <typename A, size_t N, typename T>
void Fill(A (&array)[N], const T& val) {
    std::fill((T*)array, (T*)(array + N), val);
}
bool dbg = false;
}  // namespace mydef
using namespace mydef;
#define pb push_back
#define eb emplace_back
#define lb lower_bound
#define ub upper_bound
#define all(v) (v).begin(), (v).end()
#define SZ(x) ((int)(x).size())
#define vi vector<int>
#define vvi vector<vector<int>>
#define vp vector<pair<int, int>>
#define vvp vector<vector<pair<int, int>>>
#define pi pair<int, int>
//#define P pair<int, int>
//#define V vector<int>
//#define S set<int>
#define asn ans

struct RollingHash {
private:
    using u64 = uint_fast64_t;
    using size_type = uint_fast32_t;
    using i128 = __int128_t;
    string str;
    vector<u64> hashed, power;
    static constexpr u64 mod = (1uL << 61) - 1;
    static constexpr u64 base = 1e9 + 7;
    //static constexpr u64 base = 1e9 + 9;
    static constexpr u64 mask30 = (1ul << 30) - 1;
    static constexpr u64 mask31 = (1ul << 31) - 1;
    u64 mul(i128 a, i128 b) const {
        i128 t = a * b;
        t = (t >> 61) + (t & mod);
        if (t >= mod)
            return (u64)(t - mod);
        return (u64)t;
    }
    //
public:
    void set(const string& _str) {
        str = _str;
        hashed.resize(str.size() + 1, 0);
        power.resize(str.size() + 1, 1);
        for (size_type i = 0; i < str.size(); i++) {
            hashed[i + 1] = mul(hashed[i], base) + str[i] + 1;
            power[i + 1] = mul(power[i], base);
            if (hashed[i + 1] >= mod)
                hashed[i + 1] -= mod;
        }
    }
    RollingHash() : str(){};
    RollingHash(const string& str) : str() {
        set(str);
    };
    u64 hash() const { return hashed.back(); }
    u64 hash(size_type l, size_type r) const {
        u64 ret = mod + hashed[r] - mul(hashed[l], power[r - l]);
        return ret < mod ? ret : ret - mod;
    }
    size_type size() const { return str.size(); }
};

int N;
vector<string> S;


void solve() {
    unordered_map<int, int> mp[30];
    int ans = 0;
    for (int i = 0; i < N; i++) {
        RollingHash Roll(S[i]);
        int mask = 0;
        for (int j = S[i].size() - 1; j >= -1; j--) {
            int hash = Roll.hash(0, j + 1);
            for (int x = 0; x < 26; x++) {
                if ((1 << x) & mask) {
                    if (mp[x].count(hash))
                        ans += mp[x][hash];
                }
            }
            if (j >= 0)
                mask |= 1 << S[i][j];
        }
        mp[(int)S[i].back()][Roll.hash(0, S[i].size() - 1)]++;
    }
    cout << ans << endl;
}

signed main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);


    cin >> N;
    S.resize(N);
    for (int i = 0; i < N; i++) {
        cin >> S[i];
        for (auto& s : S[i]) {
            s -= 'a';
        }
        reverse(all(S[i]));
    }
    sort(all(S), [](string x, string y) { return x.size() < y.size(); });

    solve();
    return 0;
}


Measured memory_bytes: 20636