//Δ_1004
#include<iostream>
#include<cstdio>
#include<fstream>
#include<algorithm>
#include<vector>
#include<map>
#include<set>
#include<queue>
#include<bitset>
#include<cmath>
#include<cstring>
#include<cstdlib>
using namespace std;
typedef long long LL;
typedef double DB;
const int N = 1111;
char c[11];
int n=10,m=1<<n,a[N],f[N],g[N][11];
int main()
{
    int T,i,j,l,x;
    scanf("%d",&T);
    while(T--){
        memset(a,0,sizeof(a));
        memset(f,0,sizeof(f));
        memset(g,0,sizeof(g));
        scanf("%d",&l);
        for(i=1;i<=l;i=i+1){
            scanf("%s",c+1);
            a[c[5]-'0']++;
        }
        for(i=0;i<n;i=i+1)
            f[1<<i]=a[i];
        for(i=1;i<m;i=i+1)
            f[i]=f[i&-i]+f[i^(i&-i)];
        g[0][0]=l;
        for(j=1;j<=5;j=j+1)
            for(i=0;i<m;i=i+1)
                for(x=i;x;x=(x-1)&i)
                    g[i][j]=max(g[i][j],min(g[i^x][j-1],f[x]));
        printf("%d\n",l-g[m-1][5]);
    }
    return 0;
}