Problem: A PIN code is a string that consists of exactly 4 digits. Examples of possible PIN codes: 7013, 0000 and 0990. Please note that the PIN code can begin with any digit, even with 0.

Polycarp has n (2 ≤ n ≤ 10) bank cards, the PIN code of the i-th card is p_i.

Polycarp has recently read a recommendation that it is better to set different PIN codes on different cards. Thus he wants to change the minimal number of digits in the PIN codes of his cards so that all n codes would become different.

Formally, in one step, Polycarp picks i-th card (1 ≤ i ≤ n), then in its PIN code p_i selects one position (from 1 to 4), and changes the digit in this position to any other. He needs to change the minimum number of digits so that all PIN codes become different.

Polycarp quickly solved this problem. Can you solve it?

Input

The first line contains integer t (1 ≤ t ≤ 100) — the number of test cases in the input. Then test cases follow.

The first line of each of t test sets contains a single integer n (2 ≤ n ≤ 10) — the number of Polycarp's bank cards. The next n lines contain the PIN codes p_1, p_2, ..., p_n — one per line. The length of each of them is 4. All PIN codes consist of digits only.

Output

Print the answers to t test sets. The answer to each set should consist of a n + 1 lines

In the first line print k — the least number of changes to make all PIN codes different. In the next n lines output the changed PIN codes in the order corresponding to their appearance in the input. If there are several optimal answers, print any of them.

Example

Input


3
2
1234
0600
2
1337
1337
4
3139
3139
3139
3139


Output


0
1234
0600
1
1337
1237
3
3139
3138
3939
6139

Solution (in CPP):

Solution:
#include <bits/stdc++.h>
using namespace std;
vector<vector<long long> > coprime(100001);
void prime_factorization() {
  for (long long i = 2; i <= 100001; i += 2) {
    coprime[i].push_back(2);
  }
  for (long long i = 3; i <= 100001; i += 3) {
    coprime[i].push_back(3);
  }
  for (long long i = 5; i <= 50000; i += 6) {
    if (coprime[i].size() == 0) {
      for (long long j = i; j <= 100000; j += i) {
        coprime[j].push_back(i);
      }
    }
    if (coprime[i + 2].size() == 0) {
      for (long long j = i + 2; j <= 100000; j += i + 2) {
        coprime[j].push_back(i + 2);
      }
    }
  }
}
bool isprime(long long n) {
  if (n < 2) return false;
  if (n == 2 || n == 3) return true;
  if (n % 2 == 0) return false;
  if (n % 3 == 0) return false;
  for (long long i = 5; i <= sqrt(n); i += 6) {
    if (n % i == 0 || n % (i + 2) == 0) return false;
  }
  return true;
}
void swap(long long &a, long long &b) {
  long long temp = a;
  a = b;
  b = temp;
}
long long bin_power(long long a, long long n) {
  if (a == 0) return 0;
  long long res = 1;
  while (n) {
    if (n % 2) {
      res = (res * a) % 1000000007;
      n--;
    } else {
      a = (a * a) % 1000000007;
      n /= 2;
    }
  }
  return res;
}
void p_factors(long long &n, map<long long, long long> &m) {
  if (n % 2 == 0) {
    long long c = 0;
    while (n % 2 == 0) {
      n /= 2;
      c++;
    }
    m[2] = c;
  }
  for (long long i = 3; i <= sqrt(n); i += 2) {
    if (n % i == 0) {
      long long c = 0;
      while (n % i == 0) {
        n /= i;
        c++;
      }
      m[i] = c;
    }
  }
  if (n != 1) m[n] = 1;
}
long long gcd(long long a, long long b) {
  if (b == 0) return a;
  return gcd(b, a % b);
}
long long extended_gcd(long long a, long long b, long long *x, long long *y) {
  if (a == 0) {
    *x = 0;
    *y = 1;
    return b;
  }
  long long x1, y1;
  long long g = extended_gcd(b % a, a, &x1, &y1);
  *x = y1 - (b / a) * x1;
  *y = x1;
  return g;
}
void simple_sieve(long long n, vector<long long> &primes) {
  if (n < 2) return;
  if (n < 3) {
    primes.push_back(2);
    return;
  }
  vector<bool> mark(n + 1, true);
  mark[2] = true;
  mark[3] = true;
  primes.push_back(2);
  primes.push_back(3);
  for (long long i = 5; i * i < n; i += 6) {
    if (mark[i]) {
      for (long long j = i * i; j < n; j += i) mark[j] = false;
    }
    if (mark[i + 2] && (i + 2) < sqrt(n)) {
      for (long long j = (i + 2) * (i + 2); j < n; j += (i + 2))
        mark[j] = false;
    }
  }
  for (long long i = 5; i < n; i += 6) {
    if (mark[i]) primes.push_back(i);
    if (mark[i + 2] && (i + 2) < n) primes.push_back(i + 2);
  }
}
long long linear_sieve(long long n, vector<long long> &primes) {
  if (n < 2) return 0;
  if (n < 3) {
    primes.push_back(2);
    return 1;
  }
  vector<long long> mark(n + 1);
  for (long long i = 2; i <= n; i++) {
    if (mark[i] == 0) {
      primes.push_back(i);
      mark[i] = i;
    }
    for (long long j = 0;
         j < primes.size() && primes[j] <= mark[i] && i * primes[j] <= n; j++)
      mark[i * primes[j]] = primes[j];
  }
  return primes.size();
}
void segmented_sieve(long long n, vector<long long> &primes) {
  if (n < 2) return;
  long long limit = sqrt(n) + 1;
  simple_sieve(limit, primes);
  long long low = limit;
  long long high = 2 * limit;
  while (low < n) {
    if (high >= n) high = n + 1;
    vector<bool> mark(high - low + 2, true);
    for (long long i = 0; i < primes.size(); i++) {
      long long lolim = (low / primes[i]) * primes[i];
      if (lolim < low) lolim += primes[i];
      for (long long j = lolim; j < high; j += primes[i]) mark[j - low] = false;
    }
    for (long long j = low; j < high; j++) {
      if (mark[j - low]) primes.push_back(j);
    }
    low += limit;
    high += limit;
  }
}
void ranged_primes(long long low, long long high, vector<long long> &primes) {
  if (low < 2) low = 2;
  if (high < 2) return;
  long long lim = sqrt(high);
  vector<long long> pr;
  linear_sieve(lim, pr);
  if (pr.size() == 0) {
    if (high == 2) {
      primes.push_back(2);
      return;
    }
    if (high == 3) {
      if (low <= 2) {
        primes.push_back(2);
        primes.push_back(3);
        return;
      }
      primes.push_back(3);
      return;
    }
  }
  vector<bool> mark(high - low + 1, true);
  for (auto &i : pr) {
    long long j = i * i;
    if (j < low) {
      j = (low / i) * i;
      if (j < low) j += i;
    }
    while (j <= high) {
      mark[j - low] = false;
      j += i;
    }
  }
  for (long long i = low; i <= high; i++) {
    if (mark[i - low]) primes.push_back(i);
  }
}
long long totient(long long n) {
  long long res = n;
  for (long long i = 2; i * i <= n; i++) {
    if (n % i == 0) {
      while (n % i == 0) {
        n /= i;
      }
      res -= res / i;
    }
  }
  if (n > 1) res -= res / n;
  return res;
}
void phi_1_to_n(long long n, vector<long long> &phi) {
  for (long long i = 0; i <= n; i++) {
    phi[i] = i;
  }
  for (long long i = 2; i <= n; i++) {
    if (phi[i] == i) {
      for (long long j = i; j <= n; j += i) {
        phi[j] -= phi[j] / i;
      }
    }
  }
}
long long factorial(long long n) {
  long long res = 1;
  for (long long i = 2; i <= n; i++) {
    res = (res * i) % 1000000007;
  }
  return res % 1000000007;
}
long long sumofint(long long n) {
  string s = to_string(n);
  long long sum = 0;
  for (long long i = 0; i < s.size(); i++) {
    int j = s[i];
    j -= 48;
    sum += j;
  }
  return sum;
}
long long modinverse(long long n) { return bin_power(n, 1000000007 - 2); }
long long ncr(long long n, long long r) {
  if (n < 0 || r > n || r < 0) return 0;
  if (n - r < r) r = n - r;
  vector<long long> c(n + 1);
  c[0] = 1;
  for (long long i = 1; i <= n; i++) {
    for (long long j = min(i, r); j > 0; j--) {
      c[j] = (c[j] + c[j - 1]) % 1000000007;
    }
  }
  return c[r] % 1000000007;
}
void dfsinto(long long v, vector<vector<long long> > &adj,
             vector<long long> &mark, stack<long long> &s) {
  mark[v] = 1;
  s.push(v);
  for (long long x : adj[v]) {
    if (!mark[x]) {
      dfsinto(x, adj, mark, s);
    }
  }
}
void dfs(vector<vector<long long> > &v, stack<long long> &s,
         vector<long long> &mark) {
  for (long long i = 0; i < 26; i++) {
    if (mark[i] || !v[i].size()) continue;
    dfsinto(i, v, mark, s);
  }
}
bool iscyclic(vector<vector<long long> > &g) {
  queue<long long> q;
  vector<long long> mark(26), p(26);
  for (long long i = 0; i < 26; i++) {
    if (mark[i] || !g[i].size()) continue;
    mark[i] = 1;
    q.push(i);
    p[i] = -1;
    while (!q.empty()) {
      long long f = q.front();
      q.pop();
      for (long long x : g[f]) {
        if (mark[x]) {
          if (x != p[f]) return true;
        } else {
          mark[x] = 1;
          q.push(x);
          p[x] = f;
        }
      }
    }
  }
  return false;
}
long long lcs(string &a, string &b, long long m, long long n, long long &l1,
              long long &l2) {
  vector<vector<long long> > L(n, vector<long long>(m));
  long long i, j, flag = 0;
  for (i = 0; i < m; i++) {
    for (j = 0; j < n; j++) {
      if (a[i - 1] == b[j - 1]) {
        L[i][j] = L[i - 1][j - 1] + 1;
      } else
        L[i][j] = max(L[i - 1][j], L[i][j - 1]);
    }
  }
  return L[m][n];
}
bool issorted(vector<long long> &v, long long n) {
  for (long long i = 1; i < n; i++) {
    if (v[i] < v[i - 1]) return false;
  }
  return true;
}
string lexogy(string &a, string &b) {
  long long n = a.size(), m = b.size();
  if (n < m) swap(n, m);
  for (long long i = 0; i < m; i++) {
    if (a[i] == b[i])
      continue;
    else if (a[i] < b[i])
      return a;
    else
      return b;
  }
  if (a.size() > b.size())
    return a;
  else if (b.size() > a.size())
    return b;
  else
    return "EQUAL";
}
string bin_string(long long n, long long l) {
  string s;
  for (long long i = l - 1; i >= 0; i--) {
    if (n % 2)
      s.push_back('1');
    else
      s.push_back('0');
    n /= 2;
  }
  reverse(s.begin(), s.end());
  return s;
}
int main() {
  ios_base ::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  long long tc = 1;
  cin >> tc;
  while (tc--) {
    long long n, ans = 0;
    cin >> n;
    string s[n];
    map<string, long long> m;
    vector<long long> v(10);
    for (long long i = 0; i < n; i++) {
      cin >> s[i];
      ++m[s[i]];
      ++v[s[i][3] - '0'];
    }
    auto it = m.begin();
    while (it != m.end()) {
      ans += it->second - 1;
      it++;
    }
    for (long long i = 0; i < n; i++) {
      for (long long j = i + 1; j < n; j++) {
        if (s[j] == s[i]) {
          for (long long k = 0; k < 10; k++) {
            if (v[k]) continue;
            s[j][3] = '0' + k;
            v[k] = 1;
            break;
          }
        }
      }
    }
    cout << ans << endl;
    for (long long i = 0; i < n; i++) cout << s[i] << endl;
  }
  return 0;
}