#include <bits/stdc++.h>
#define dbg(x) cerr << #x << ':' << (x) << endl; 
using namespace std;
using ll = long long;
using ld = long double;
#define ALL(x) x.begin(),x.end()

int main()
{
    int n;
    cin >> n;

    vector<string> s(n);
    for (int i = 0; i < n; i++) cin >> s[i];

    int sz = 26;

    vector<vector<int>> z_hash(s[0].size(),vector<int>(sz));
    mt19937 mt_random(0);
    for (int i = 0; i < s[0].size(); i++) {
        for (int j = 0; j < sz; j++) {
            z_hash[i][j] = mt_random();
        }
    }
    vector<vector<int>> h(s[0].size(), vector<int>(n));
    for (int i = 0; i < s[0].size()-1; i++) {
        for (int j = 0; j < n; j++) {
            for (int k = 0; k < s[0].size(); k++) {
                if (i == k || i+1 == k) continue;
                h[i][j] ^= z_hash[k][s[j][k]-'A'];
            }
        }
    }

    auto func = [](char a, char b){
        return (a-'A')*26 + (b-'A');
    };

    vector<vector<vector<int>>> v(s[0].size(), vector<vector<int>>(sz*sz, vector<int>(sz*sz)));
    for (int i = 0; i < s[0].size()-1; ++i) {
        
        for (int j = 0; j < n; ++j) {
            int tmp1 = func(s[j][i],s[j][i+1]);
            for (int k = j+1; k < n; ++k) {
                int tmp2 = func(s[k][i],s[k][i+1]);
                if (h[i][j] != h[i][k]) continue;
                if (tmp1 == tmp2) continue;
                if (tmp1 < tmp2) v[i][tmp1][tmp2]++;
                else v[i][tmp2][tmp1]++;
            }
        }
    }

    int ans = 0;
    for (int i = 0; i < n; i++) {
        for (int j = i+1; j < n; j++) {
            for (int k = 0; k < s[0].size()-1; k++) {
                int tmp1 = func(s[i][k],s[i][k+1]);
                int tmp2 = func(s[j][k],s[j][k+1]);
                if (h[k][i] != h[k][j]) continue;
                if (tmp1 == tmp2) continue;
                
                if (tmp1 < tmp2) {
                    if (v[k][tmp1][tmp2] == 1) {
                        ++ans;
                        break;
                    }
                }
                else {
                    if (v[k][tmp2][tmp1] == 1) {
                        ++ans;
                        break;
                    }
                }
            }
        }
    }

    cout << ans << endl;

}