#include <bits/stdc++.h>
using namespace std;
using ll = long long;

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n;
    cin >> n;
    vector<string> A(n);
    for(auto &&str : A) cin >> str;
    int b = 2 * (n - 1), ans = 0;
    string tmp(b + 1, '?');
    auto check = [&](){
        int l = 0, r = tmp.size() - 1;
        while(l < r){
            if(tmp[l] != tmp[r]) return false;
            l++, r--;
        }
        return true;
    };
    for(int comb = (1 << (n - 1)) - 1; comb < (1 << b); ){
        {
            int y = 0, x = 0;
            for(int i = 0; i < b; i++){
                tmp[i] = A[y][x];
                if(comb >> i & 1) x++;
                else y++;
            }
            tmp.back() = A[y][x];
            ans += check();
        }
        int x = comb & (-comb), y = comb + x;
        comb = ((comb & ~y) / x >> 1) | y;
    }
    cout << ans << '\n';
}