#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
char s1[105][105],s2[105][105];
int n,m,flag[205][205],head[205],ma[205],vis[205],ans[205];
int dfs(int u)
{
    //printf("%d\n",u);
    for (int i=1;i<=m;i++)
    {
        if (flag[u][i+m])
        {
            if (vis[i+m]) continue;
            vis[i+m]=1;
            if (ma[i+m]==-1||dfs(ma[i+m]))
            {
                ma[i+m]=u;
                return 1;
            }
        }
    }
    return 0;
}
int main()
{
    int cas;
    scanf("%d",&cas);
    while (cas--)
    {
        scanf("%d%d",&n,&m);
        for (int i=1;i<=n;i++) scanf("%s%s",s1[i]+1,s2[i]+1);
        memset(flag,0,sizeof(flag));
        for (int i=1;i<=m;i++)
            for (int j=1;j<=m;j++)
            {
                for (int k=1;k<=n;k++)
                {
                    if (s1[k][i]!=s2[k][j])
                    {
                        goto fail;
                    }        
                    
                }
                flag[i][j+m]=1;
                //printf("%d %d\n",i,j);
                fail:;
            }
        int Ans=0;
        memset(ma,-1,sizeof(ma));
        for (int i=m;i;i--)
        {
            for (int j=1;j<=m+m;j++) vis[j]=0;
            Ans+=dfs(i);
        }
        if (Ans==m)
        {
            for (int i=1;i<=m;i++) ans[ma[i+m]]=i;
            for (int i=1;i<m;i++) printf("%d ",ans[i]);
            printf("%d\n",ans[m]);
        }
        else puts("-1");
    }
    return 0;
}