#include <cstdio>
#include <algorithm>
#include <vector>
#include <cstring> 
#define RI register int

using namespace std;

int cnt[15];
int sum[1 << 10];
int f[6][1 << 10];
char s[15];

int main() {
    //freopen("a.in", "r", stdin); 
    int T; scanf("%d", &T);
    while (T--) {
        memset(cnt, 0, sizeof(cnt));
        memset(sum, 0, sizeof(sum));
        memset(f, 0, sizeof(f));
        int n; scanf("%d", &n);
        for (RI i = 1; i <= n; ++i) {
            scanf("%s", s + 1);
            ++cnt[s[5] - '0'];
        }
        int all = 1 << 10;
        for (RI i = 0; i < all; ++i)
            for (RI j = 0; j < 10; ++j)
                if ((i >> j) & 1)
                    sum[i] += cnt[j];
        f[0][0] = 0x3f3f3f3f;
        for (RI i = 1; i <= 5; ++i)
            for (RI s1 = 0; s1 < all; ++s1)
                for (RI s2 = 0; s2 < all; ++s2)
                    if ((s1 & s2) == 0)
                        f[i][s1 | s2] = max(f[i][s1 | s2], min(f[i - 1][s1], sum[s2]));
        printf("%d\n", n - f[5][all - 1]);
    }
    return 0;
}