#include <bits/stdc++.h>

#define f first
#define s second
#define pb push_back
#define mp make_pair

using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<long long, long long> pll;

const int N = 300500, inf = 1e9, mod = 998244353;
const ll INF = 1e18;

int sum(int a, int b) {
    a += b;
    if (a >= mod)
        a -= mod;
    return a;
}

int sub(int a, int b) {
    a -= b;
    if (a < 0)
        a += mod;
    return a;
}

int mult(int a, int b) {
    return 1ll * a * b % mod;
}

int bp(int a, int b) {
    int res = 1;
    while (b) {
        if (b & 1)
            res = mult(res, a);
        a = mult(a, a);
        b >>= 1;
    }
    return res;
}

int inv(int x) {
    return bp(x, mod - 2);
}

int n;
const int maxN = 1005;
string X[maxN];
bool bad[18][18];
char bck[18];
bool used[18];
int id[18];
int ans[18];
int cnt[3];
bool fnd = false;
void rec(int v) {
    if (v == 18) {
        fnd = true;
        for (int z = 0; z < 18; z++) ans[z] = id[z];
        return;
    }
    for (int r = 0; r < 3; r++) {
        if (cnt[r] == 6) continue;
        bool can = true;
        for (int z = 0; z < v; z++) {
            if  (id[z] == r && bad[v][z]) {
                can = false;
                break;
            }
        }
        if (can) {
            cnt[r]++;
            id[v] = r;
            rec(v + 1);
            cnt[r]--;
        }
    }
}
void solve() {
    cin >> n;
    map<char,int> s;
    int sz = 0;
    for (int i = 0; i < n; i++) {
        cin >> X[i];
        for (auto& it : X[i]) {
            if (!s.count(it)) {
                s[it] = sz;
                sz++;
            }
        }
    }
    if (s.size() > 18) {
        cout << 0;
        return ;
    }
    for (char x = 'a'; x <= 'z'; x++) {
        if (sz < 18 && !s.count(x)) {
            s[x] = sz;
            sz++;
        }
    }
    for (int i = 0; i < n; i++) {
        for (int a = 0; a < 3; a++) {
            for (int b = a + 1; b < 3; b++) {
                bad[s[X[i][a]]][s[X[i][b]]] = true;
                bad[s[X[i][b]]][s[X[i][a]]] = true;
//                cout << " HI " << s[X[i][a]] << " " << s[X[i][b]] << endl;
            }
        }
    }
    for (int i = 0; i < 18; i++) {
        if (bad[i][i]) {
            cout << 0;
            return ;
        }
    }
    for (auto& it : s) {
        bck[it.second] = it.first;
    }
    rec(0);
    if (!fnd) {
        cout << 0 << '\n';
    }
    else {
        vector<vector<char>> ANS(3);
        for (int t = 0; t < 18; t++) {
            ANS[ans[t]].emplace_back(bck[t]);
        }
        for (int p = 0; p < 3; p++) {
            assert(ANS[p].size() == 6);
            for (char& t : ANS[p]) cout << t;
            if (p != 2) {
                cout << " ";
            }
        }
    }
}

int main() {
#ifdef DEBUG
    freopen("input.txt", "r", stdin);
#endif
    ios_base::sync_with_stdio(false);
    int t = 1;
//    cin >> t;
    for (int i = 1; i <= t; i++) {
//        cout << "Case #" << i << endl;
        solve();
    }
}