#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <random>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }
#define COLOR(s) ("\x1b[" s "m")


namespace bm {
constexpr int LIM_N0 = 130 * 130;
constexpr int LIM_N1 = 130;
int n0, n1;
bitset<LIM_N1> adj[LIM_N0];
int to[LIM_N0], fr[LIM_N1];
int zeit, used[LIM_N0];
void init(int n0_, int n1_) {
  n0 = n0_; n1 = n1_;
  for (int u = 0; u < n0; ++u) adj[u].reset();
}
void ae(int u, int v) {
  adj[u].set(v);
}
int augment(int u) {
  used[u] = zeit;
  for (int v = 0; v < n1; ++v) if (adj[u][v]) {
    const int w = fr[v];
    if (!~fr[v] || (used[w] != zeit && augment(w))) {
      to[u] = v; fr[v] = u; return 1;
    }
  }
  return 0;
}
int run() {
  memset(to, ~0, n0 * sizeof(int));
  memset(fr, ~0, n1 * sizeof(int));
  memset(used, ~0, n0 * sizeof(int));
  int tof = 0;
  for (zeit = 0; zeit < n0; ++zeit) tof += augment(zeit);
  return tof;
}
}  // namespace bm


constexpr int MAX_U = 130 * 130 * 130;
constexpr int A = 52;
int tr(char c) {
  return isupper(c) ? (0 + (c - 'A')) : (26 + (c - 'a'));
}
char rt(int a) {
  return (a < 26) ? ('A' + (a - 0)) : ('a' + (a - 26));
}

int U;
int nxt[MAX_U][A];
pair<int, int> prv[MAX_U];
int zeit, used[MAX_U];
int newNode() {
  const int u = U++;
  fill(nxt[u], nxt[u] + A, -1);
  used[u] = 0;
  return u;
}
int go(int u, int a) {
  int &v = nxt[u][a];
  if (!~v) {
    v = newNode();
    prv[v] = make_pair(u, a);
  }
  return v;
}
void init() {
  U = 0;
  zeit = 0;
  newNode();
}

char buf[130 * 130];
char *readln() {
  return fgets(buf, sizeof(buf), stdin);
}

int N;
vector<vector<string>> S;

int main() {
  for (; readln(); ) {
    N = atoi(buf);
    S.assign(N, {});
    for (int i = 0; i < N; ++i) {
      readln();
      istringstream iss(buf);
      for (string s; iss >> s; S[i].push_back(s)) {}
    }
// cerr<<"S = "<<S<<endl;
    
    init();
    // (depth, u)
    vector<vector<pair<int, int>>> graph(N);
    for (int i = 0; i < N; ++i) {
      const int lim = (int)S[i].size() + N + 1;
      // depth -> u
      vector<vector<int>> uss(lim);
      uss[0].push_back(0);
      for (const string &s : S[i]) {
        ++zeit;
        int cnt = 0;
        vector<vector<int>> vss(lim);
        // (node, pos in s)
        vector<pair<int, int>> ps;
        for (int d = 0; d < lim; ++d) {
          for (const int u : uss[d]) ps.emplace_back(u, 0);
          vector<pair<int, int>> qs;
          for (const auto &p : ps) if (p.second < (int)s.size()) {
            const int u = p.first;
            const int a = tr(s[p.second]);
            const int v = go(u, a);
            if (used[v] != zeit) {
              vss[d + 1].push_back(v);
              if (++cnt == N) goto done;
              qs.emplace_back(v, p.second + 1);
            }
          }
          ps.swap(qs);
        }
       done:{}
// cerr<<"vss = "<<vss<<endl;
        uss.swap(vss);
      }
      for (int d = 0; d < lim; ++d) for (const int u : uss[d]) graph[i].emplace_back(d, u);
    }
    
    vector<pair<int, int>> dus;
    for (int i = 0; i < N; ++i) for (const auto &du : graph[i]) dus.push_back(du);
    sort(dus.begin(), dus.end());
    dus.erase(unique(dus.begin(), dus.end()), dus.end());
    const int dusLen = dus.size();
    // greedy for dus
    bm::init(dusLen, N);
    for (int i = 0; i < N; ++i) for (const auto &du : graph[i]) {
      const int j = lower_bound(dus.begin(), dus.end(), du) - dus.begin();
      bm::ae(j, i);
    }
    const int res = bm::run();
    if (res == N) {
      for (int i = 0; i < N; ++i) {
        const int j = bm::fr[i];
        assert(~j);
        string t;
        for (int v = dus[j].second; v; ) {
          const int u = prv[v].first;
          const int a = prv[v].second;
          t += rt(a);
          v = u;
        }
        reverse(t.begin(), t.end());
        puts(t.c_str());
      }
    } else {
      puts("no solution");
    }
  }
  return 0;
}