#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

void bins(int col, int minRow, int maxRow);

int n;
vector<string> vs(2e5);
unsigned long long ans;

int main() {
    cin >> n;
    vs.resize(n);
    for (int i = 0; i < n; i++) {
        cin >> vs[i];
    }
    sort(vs.begin(), vs.end());
    
    // for (int i = 0; i < n; i++) cout << vs[i] << endl;
    
    bins(0, 0, n-1);
    
    cout << ans << endl;
    return 0;
}

void bins(int col, int minRow, int maxRow) {
    for (char ch = 'a'; ch <= 'z'; ch++) {
        int lRow = 0, hRow = 0;
        for (int b=25; b >=0; b--) {
            int u = lRow | (1 << b);
            int v = hRow | (1 << b);
            if (minRow <= u && u <= maxRow) {
                if (vs[u].size() <= col || vs[u][col] < ch) {
                    lRow = u;
                }
            }
            if (minRow <= v && v <= maxRow) {
                if (vs[v].size() <= col || vs[v][col] <= ch) {
                    hRow = v;
                }
            }
        }
        if (vs[hRow].size() <= col || vs[hRow][col] != ch) { continue; }
        if (vs[lRow].size() <= col || vs[lRow][col] != ch) { lRow++; }
        unsigned long long len = hRow - lRow + 1;
        // cout << "[" << col << "] " << ch << ": " << lRow << ", " << hRow << ", (" << len << ")" << endl;
        if (len == 1ULL) {
            ans += (unsigned long long)vs[hRow].size() - (unsigned long long)col;
        } else if (len > 1ULL) {
            unsigned long long lp = 1, rp = len;
            while (lp <= rp) {
                ans += lp * rp * (lp == rp ? 1ULL : 2ULL);
                lp++; rp--;
            }
            bins(col + 1, lRow, hRow);
        }
    }
}