#include<bits/stdc++.h>
#define ll long long
#define ull unsigned ll
#define uint unsigned
#define pii pair<int,int>
#define pll pair<ll,ll>
#define IT iterator
#define PB push_back
#define fi first
#define se second
#define For(i,j,k) for (int i=(int)(j);i<=(int)(k);i++)
#define Rep(i,j,k) for (int i=(int)(j);i>=(int)(k);i--)
#define CLR(a,v) memset(a,v,sizeof(a));
#define CPY(a,b) memcpy(a,b,sizeof(a));
#define debug puts("wzpakking")
#define y1 ysghysgsygsh 
using namespace std;
int n,s[15],f[10][1055];
void solve(){
    scanf("%d",&n);
    memset(s,0,sizeof(s));
    memset(f,30,sizeof(f));
    For(i,1,n){
        char t[10];
        scanf("%s",t+1);
        ++s[t[5]-'0'];
    }
    f[0][0]=0;
    For(i,0,1023){
        int sum=0;
        For(j,0,9) if (i&(1<<j)); else sum+=s[j];
        For(j,0,1023) if ((i&j)==0)
            For(k,0,4) f[k+1][i|j]=min(f[k+1][i|j],max(f[k][j],sum));
    }
    cout<<f[5][1023]<<endl;
}
int main(){
    int T;
    scanf("%d",&T);
    while (T--) solve();
}