#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
#define mem(x,v) memset(x,v,sizeof(x))
#define Rep(i,a,b) for(register int i=(a);i<=int(b);++i)
#define rep(i,a,b) for(register int i=(a);i<int(b);++i)
#define Dep(i,a,b) for(register int i=(a);i>=int(b);--i)
#define gc getchar
#define pc putchar
#define fi first
#define se second
inline ll read(){
    ll x=0,f=1;char c=gc();
    for(;!isdigit(c);c=gc())if(c=='-')f=-1;
    for(;isdigit(c);c=gc())x=(x<<1)+(x<<3)+(c^48);
    return x*f;
}
inline void write(ll x){if(x<0)x=-x,pc('-');if(x>=10)write(x/10);putchar(x%10+'0');}
inline void writeln(ll x){write(x);pc('\n');}
inline void wri(ll x){write(x);pc(' ');}
#define link LINK
const int maxv = 505;
int n,m;
int mark[maxv][maxv],link[maxv],ans[maxv];
bool vis[maxv];   
bool Hungary(int u){  
    for (int v=1;v<=m;v++){  
        if (!vis[v] && mark[u][v]){  
            vis[v] = true;  
            if (link[v] == -1 || Hungary(link[v])){  
                link[v] = u;  
                return true;  
            }  
        }  
    }  
    return false;  
}  
int get(int st){
    int ans = 0;
    Rep(k,st,m){
        memset(vis,false,sizeof(vis));
        if(Hungary(k))ans++;
    }
    return ans;
}
void calc(){
    memset(ans,-1,sizeof(ans));
    memset(link,-1,sizeof(link));
    if(get(1) != m){
        puts("-1");
        return ;
    }
    Rep(i,1,m){
        Rep(j,1,m){
            if(ans[j]==-1 && mark[i][j]){
                ans[j] = i;
//                printf("{%d %d}\n",i,j);
                Rep(k,1,m) link[k] = ans[k];
                if(i + get(i) == m) break;
//                puts("not break");
                ans[j] = -1;
            }
        }
    }
    Rep(i,1,m) link[ans[i]] = i;
    Rep(i,1,m-1) wri(link[i]);
    writeln(link[m]);
    return ; 
}
void solve(){
    n = read(),m = read();
    Rep(i,1,m)Rep(j,1,m)mark[i][j]=true;
    char a[55],b[55];
    Rep(i,1,n){
        scanf("%s",a+1);
        scanf("%s",b+1);
        Rep(i,1,m)
            Rep(j,1,m)
                if(a[i]!=b[j]) mark[i][j]=false;
    }
    calc();
}
int main(){
    int T = read();
    while(T--){
        solve();
    }
    return 0;
}