#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
#define N 205
int n,m,k,l,t,s,T;
char s1[N][N],s2[N][N];
int flag[N],f[N],a[N][N],ans[N];
int find(int u){
    for (int v=1;v<=n;v++)
        if(a[u][v]&&!flag[v]){
            flag[v]=1;
            if(f[v]==0||find(f[v])){
            f[v]=u;
            return 1;
            }
        }
    return 0;
}
int main(){
    scanf("%d",&T);
    while(T--){
        s=0;
        memset(f,0,sizeof(f));
        memset(a,0,sizeof(a));
        scanf("%d%d",&m,&n);
        for (int i=1;i<=m;i++)scanf("%s%s",s1[i]+1,s2[i]+1);
        for (int i=1;i<=n;i++)
            for (int j=1;j<=n;j++){
                int p=1;
                for (int k=1;k<=m;k++)if(s1[k][i]!=s2[k][j])p=0;
                if(p)a[i][j]=1;
            }
        for (int i=n;i;i--){
            memset(flag,0,sizeof(flag));
            s+=find(i);
        }
        if(s<n){puts("-1");continue;}
        for (int i=1;i<=n;i++)ans[f[i]]=i;
        for (int i=1;i<n;i++)printf("%d ",ans[i]);
        printf("%d\n",ans[n]);
    }
}