# include <bits/stdc++.h>
using namespace std;
# define rep(i,a,n) for (int i=a; i<=n; ++i)
# define per(i,a,n) for (int i=a; i>=n; --i)
# define bug puts("H");
# define pb push_back
# define mp make_pair
# define all(x) (x).begin(), (x).end()
# define SZ(x) (int)x.size()
# define fi first
# define se second
# define lch p<<1,l,mid
# define rch p<<1|1,mid+1,r
# define mem(a,b) memset(a,b,sizeof(a))
# define INF 1000000001
# define MOD 1000000007
typedef vector<int> Vi;
typedef long long i64;
typedef pair<int, int> Pi;
i64 powmod(i64 a, i64 b){i64 res=1;a%=MOD;assert(b>=0);for(;b;b>>=1){if(b&1)res=res*a%MOD;a=a*a%MOD;}return res;}
i64 Inv(i64 b){return powmod(b,(i64)MOD-2);}
const int N = 20005;
const double eps = 1e-9;

int num[15];
char tmp[8];
int dp[6][1<<10];

int main ()
{
    int T;
    scanf("%d", &T);
    while (T--) {
        int n;
        scanf("%d", &n);
        mem(num,0);
        rep(i,1,n) scanf("%s", tmp), ++num[tmp[4]-'0'];
        int top = (1<<10);
        rep(i,1,5) rep(j,0,top-1) dp[i][j] = INF;
        rep(i,1,5) {
            rep(j,0,top-1) {
                for (int k = j; k; k = (k-1) & j) {
                    int t = 0;
                    rep(l,0,9) if (((k>>l)&1) == 0) t+=num[l];
                    dp[i][j] = min(dp[i][j], max(dp[i-1][j^k],t));
                }
                dp[i][j] = min(dp[i][j], n);
            }
        }
        int ans = INF;
        rep(i,0,top-1) ans = min(ans, dp[5][i]);
        printf("%d\n", ans);
    }
    return 0;
}