#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int,int> pii;
#define fir first
#define sec second
#define rep(i,a,b) for (int i = (a); i <= (b); ++ i)
#define rrp(i,a,b) for (int i = (a); i >= (b); -- i)
#define gc() getchar()
template <typename tp>
inline void read(tp& x) {
  x = 0; char tmp; bool key = 0;
  for (tmp = gc(); !isdigit(tmp); tmp = gc())
    key = (tmp == '-');
  for (; isdigit(tmp); tmp = gc())
    x = (x << 3) + (x << 1) + (tmp ^ '0');
  if (key) x = -x;
}
template <typename tp>
inline void ckmn(tp& x,tp y) {
  x = x < y ? x : y;
}
template <typename tp>
inline void ckmx(tp& x,tp y) {
  x = x < y ? y : x;
}


int n, num[10];
bool dp[10][1 << 10];
bool check(int lim) {
  memset(dp, 0, sizeof dp);
  dp[0][0] = true;
  rep (i, 1, 5) {
    rep (j, 0, (1 << 10) - 1) if (dp[i-1][j]) {
      int t = ((1 << 10) - 1) ^ j;
      for (int s = t; true; s = (s - 1) & t) {
    int tmp = n;
    rep (a, 0, 9) if ((s >> a)&1) tmp -= num[a];
    if (tmp <= lim) dp[i][j | s] = true;
    if (s == 0) break;
      }
    }
  }
  rep (j, 0, (1 << 10) - 1) if (dp[5][j])
    return true;
  return false;
}
void solve() {
  read(n);
  memset(num, 0, sizeof num);
  string tmp;
  rep (i, 1, n) {
    cin >> tmp;
    int t = (int)tmp.size()-1;
    ++ num[tmp[t] - '0'];
  }
  int l = 1, r = n, ans = n;
  while (l <= r) {
    int mid = (l + r) >> 1;
    if (check(mid)) r = mid - 1, ans = mid;
    else l = mid + 1;
  }
  printf("%d\n", ans);
}
int main() {
  int T;
  read(T);
  while (T --)
    solve();
  return 0;
}