/*

Author: Haze

2024/5/23

*/

#include <bits/stdc++.h>

using namespace std;


struct node {
    map<char, int> child;
    int val;

    node() {
        child.clear();
        val = 0;
    }
};


class tire {
private:
    vector<node> tree;
    int tot = 0;
public:
    tire(int n, int k) {
        tree.resize((n * n / 2 + 10) * k);
    }

    void insert(string &s) {
        int now = 0;
        for (auto i: s) {
            if (!tree[now].child.contains(i)) {
                tree[now].child[i] = ++tot;
            }
            now = tree[now].child[i];
        }
        tree[now].val++;
    }

    bool query(string &s) {
        int now = 0;
        for (auto i: s) {
            if (!tree[now].child.contains(i)) {
                tree[now].child[i] = ++tot;
            }
            now = tree[now].child[i];
        }
        return tree[now].val == 1;
    }

};

string ss(string s1, string s2) {
    if (s1 > s2) {
        swap(s1, s2);

    }
    int l = 0, r = s1.length() - 1;
    while (s1[l] == s2[l])l++;
    while (s1[r] == s2[r])r--;
    string s = s1.substr(l, r - l + 1) + s2.substr(l, r - l + 1);
    return s;
}


void solve() {
    int n;
    cin >> n;
    vector<vector<string>> arr(22);
    for (int i = 1; i <= n; i++) {
        string s;
        cin >> s;
        arr[s.length()].emplace_back(s);
    }
    int ans = 0;
    for (int i = 3; i <= 20; i++) {
        if (arr[i].size() > 1) {
            tire t(arr[i].size(), i);
            for (int j = 0; j < arr[i].size(); j++) {
                for (int k = j + 1; k < arr[i].size(); k++) {
                    string sss = ss(arr[i][j], arr[i][k]);
//                cout << sss << endl;
                    if (sss.size() == i + i)continue;
                    t.insert(sss);
                }
            }
            for (int j = 0; j < arr[i].size(); j++) {
                for (int k = j + 1; k < arr[i].size(); k++) {
                    string sss = ss(arr[i][j], arr[i][k]);

                    if (sss.size() == i + i)continue;
                    if (t.query(sss)) {
                        ans++;
                    }
                }
            }
        }

    }

    cout<<ans<<endl;
};

int main() {
    ios::sync_with_stdio(0), cin.tie(0);

    int T = 1;
    while (T--) {
        solve();
    }
    return 0;
}