#include <bits/stdc++.h>
using namespace std;
#define mp make_pair
#define pb push_back
#define x first
#define y second
typedef pair<int,int> pii;
typedef long long ll;
typedef unsigned long long ull;
template <typename T> void chkmax(T &x,T y){x<y?x=y:T();}
template <typename T> void chkmin(T &x,T y){x>y?x=y:T();}
template <typename T> void readint(T &x)
{
    x=0;int f=1;char c;
    for(c=getchar();!isdigit(c);c=getchar())if(c=='-')f=-1;
    for(;isdigit(c);c=getchar())x=x*10+c-'0';
    x*=f;
}
/*const int MOD=;
inline int dmy(int x){return x>=MOD?x-MOD:x;}
inline void inc(int &x,int y){x=dmy(x+y);}
int qmi(int x,int y)
{
    int ans=1;
    for(;y;y>>=1,x=1ll*x*x%MOD)
        if(y&1)ans=1ll*ans*x%MOD;
    return ans;
}*/ 
const int MAXN=10005;

int n,cnt[10];
char str[10];
int d[1<<10],f[6][1<<10];
void solve()
{
    memset(cnt,0,sizeof(cnt));
    readint(n);
    for(int i=1;i<=n;++i)scanf("%s",str),++cnt[str[4]-'0'];
    d[0]=0;
    for(int s=1;s<(1<<10);++s)
        for(int i=0;i<10;++i)
            if(s&(1<<i))
            {
                d[s]=d[s^(1<<i)]+cnt[i];
                break;
            }
    f[0][0]=1<<30;
    for(int i=1;i<=5;++i)
        for(int s=0;s<(1<<10);++s)
        {
            f[i][s]=min(f[i-1][0],d[s]);
            for(int t=s;t;t=(t-1)&s)
                chkmax(f[i][s],min(f[i-1][t],d[s^t]));
        }
    printf("%d\n",n-f[5][1023]);
}

int main()
{
    #ifdef LOCAL
    freopen("code.in","r",stdin);
//    freopen("code.out","w",stdout);
    #endif
    int T;
    readint(T);
    while(T--)solve();
    return 0;
}