#include<stdio.h>
#include<stdlib.h>
#include<algorithm>
#include<math.h>
#include<string.h>
#include<string>
#include<time.h>
#include<stack>
#include<map>
#include<set>
#include<queue>
#include<unordered_map>
#include<ctype.h>
#include<random>
#include<iostream>
using namespace std;
typedef long long ll;
typedef double db;
#define _Zero(a) memset(a,0,sizeof(a))
#define _Neg1(a) memset(a,-1,sizeof(a))
#define _Inf(a) memset(a,0x3f,sizeof(a))
#define _NegInf(a) memset(a,0xcf,sizeof(a))
#define _Rep(i,a,b) for(int (i)=(a);(i)<=(b);i++)
#define _Dep(i,a,b) for(int (i)=(a);(i)>=(b);i--)
#define _Out(a)    cerr<<(#a)<<" = "<<(a)<<endl
const int INF = 0x3f3f3f3f;
const int MAXN = 1e5 + 50;
const ll LINF = 0x3f3f3f3f3f3f3f3f;
const ll MOD = 1e9 + 7;
const db EPS = 1e-6;
const db Pi = acos(-1);
void test() { cerr << "\n"; }
template <typename T,typename...Args>void test(T x,Args...args){cerr<<x<<" ";test(args...); }
ll qpow(ll a, ll b) {return b?((b&1)?a*qpow(a*a%MOD,b>>1)%MOD : qpow(a*a%MOD,b>>1))%MOD :1; }
ll qpow(ll a, ll b, ll c) {return b?((b&1)?a*qpow(a*a%c,b>>1)%c : qpow(a*a%c,b>>1)) % c: 1; }
ll gcd(ll a, ll b){return b?gcd(b,a% b): a; }
int sign(db x) { return x<-EPS ? -1: x>EPS; }
int dbcmp(db l, db r) { return sign(l - r); }

const int maxn=10010;
vector<int> line[maxn];
int boy[maxn];
int girl[maxn];
int used[maxn];
int n,m;


bool dfs(int x)
{
    for(int i=1;i<=m;i++)
    {
        if(used[i]==0)
        {
            if(count(line[x].begin(),line[x].end(),i)!=0)
            {
                used[i]=1;
                if(boy[i]==0 || dfs(boy[i])==1)
                {
                    boy[i]=x;
                    girl[x]=i;
                    return 1;
                }
            }
        }
    }
    return 0;
}

vector <int> ans;
int G[55][55];
int main()
{
    int T;
    scanf("%d",&T);
    while(T--)
    {
        _Zero(boy);_Zero(girl);_Zero(used);
        scanf("%d%d",&n,&m);
        for(int i=1;i<=m;i++)
        {
            for(int j=1;j<=m;j++)
                G[i][j]=1;
            line[i].clear();
        }
        for(int x=1;x<=n;x++)
        {
            char S[55],T[55];
            scanf("%s%s",S+1,T+1);
            set<int>st[33];
            for(int i=1;T[i];i++)
                st[T[i]-'a'].insert(i);
            for(int i=1;S[i];i++)
            {
                for(int j=1;j<=m;j++)
                {
                    if(!st[S[i]-'a'].count(j))G[i][j]=0;
                }
            }
        }
        for(int i=1;i<=m;i++)
        {
            for(int j=1;j<=m;j++)
            {
                if(G[i][j])
                {
                    line[i].push_back(j);
                    //printf("(%d,%d)",i,j);
                }
            }
        }
        bool f=1;
        for(int i=m;i>=1;i--)
        {
            _Zero(used);

           // for(int j=0;j<line[i].size();j++)printf("%d ",line[i][j]);
      //      putchar(10);
            if(dfs(i)==0)f=0;
        }
        if(f)
        {
            for(int i=1;i<=m;i++)
            {
                printf("%d%c",girl[i],i==m?'\n':' ');
            }
        }
        else printf("-1\n");
    }
}
/*

*/