#include<iostream>
#include <string>
#include<bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimization ("unroll-loops")
#define ll long long int
#define ld long double
#define pb push_back
#define endl "\n"
#define mp make_pair
#define sz(v) (int)(v.size())
#define len(s) (int)(s.length())
#define M 1000000007
#define all(v) v.begin(),v.end()
#define fr(a,b,c) for(ll i=a;i<=b;i+=c)
#define inarr(arr,n); for(ll i=0;i<n;i++) cin >> arr[i];
#define outarr(arr,n); for(ll i=0;i<n;i++) cout<<arr[i]<<" ";
#define ios ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
const ll inf = 9e18;
const ld pi = 2*acos(0.0); 
using namespace std;
ll power(ll a,ll n) 
{
    if(n==0){
        return 1;
    }
    ll p=power(a,n/2) % M;
    p = (p * p) % M;
    if (n%2==1)
    {
        p=(p*a)%M;
    }
    return p;
}
ll gcd(ll a, ll b) 
{ 
    if (a == 0) 
        return b; 
    return gcd(b % a, a); 
}
const int N=1e6+5;
vector <ll> sieve(N,0); 
void si() 
{
    sieve[1]=1;
    for(int i=2;i<N;i++){
        if(sieve[i]==0){
            sieve[i]=i;
            for(int j=2*i;j<N;j+=i){
                sieve[j]=i;
            }
        }
    }
}
int isprime(ll n){
    for(ll i=2;i*i<=n;i++){
        if(n%i==0){
            return 0;
        }
    }
    return 1;
}
int main(){
    ios;
    int t;
    cin>>t;
    while(t--){
        int n,m;
        cin>>n>>m;
        vector <string> a(n);
        inarr(a,n);
        if(m%2==1){
            cout<<"YES"<<endl;
            for(int i=1;i<=m+1;i++){
                cout<<(i+2)/2 - (i-1)/2<<" ";
            }
            cout<<endl;
        }
        else{
            int flag=0;
            vector <pair<ll,ll> > counta(n,mp(0,0));
            vector <pair<ll,ll> > countb(n,mp(0,0));
            for(int i=0;i<n;i++){
                for(int j=0;j<n;j++){
                    if(i!=j){
                        if(a[i][j]=='a'){
                            counta[i].first+=1;
                            counta[j].second+=1;
                        }
                        else{
                            countb[i].first+=1;
                            countb[j].second+=1;
                        }
                    }
                }
            }
            ll vertex1=-1,vertex2=-1,vertex3=-1;
            for(int i=0;i<n;i++){
                for(int j=0;j<n;j++){
                    if(i!=j){
                        if(a[i][j]==a[j][i]){
                            flag=1;
                            vertex1=i+1;
                            vertex2=j+1;
                            vertex3=i+1;
                            break;
                        }
                    }
                    if(flag==1){
                        break;
                    }
                }
            }
            if(flag==1){
                cout<<"YES"<<endl;
                for(int i=1;i<=m+1;i++){
                    if(i%2==1){
                        cout<<vertex1<<" ";
                    }
                    else{
                        cout<<vertex2<<" ";
                    }
                }
                cout<<endl;
                continue;
            }
            for(int i=0;i<n;i++){
                if(counta[i].first>0 && counta[i].second>0){
                    vertex1=i+1;
                    flag=1;
                    for(int j=0;j<n;j++){
                        if(a[i][j]=='a'){
                            vertex3=j+1;
                            break;
                        }
                    }
                    for(int j=0;j<n;j++){
                        if(a[j][i]=='a'){
                            vertex2=j+1;
                            break;
                        }
                    }
                    break;
                }
                if(countb[i].first>0 && countb[i].second>0){
                    vertex1=i+1;
                    flag=1;
                    for(int j=0;j<n;j++){
                        if(a[i][j]=='b'){
                            vertex3=j+1;
                            break;
                        }
                    }
                    for(int j=0;j<n;j++){
                        if(a[j][i]=='b'){
                            vertex2=j+1;
                            break;
                        }
                    }
                    break;
                }
            }
            if(flag==0){
                cout<<"NO"<<endl;
            }
            else{
                cout<<"YES"<<endl;
                m=m/2;
                if(m%2==0){
                    for(int i=1;i<=m;i++){
                        if(i%2==1){
                            cout<<vertex1<<" ";
                        }
                        else{
                            cout<<vertex2<<" ";
                        }
                    }
                    cout<<vertex1<<" ";
                    for(int i=1;i<=m;i++){
                        if(i%2==1){
                            cout<<vertex3<<" ";
                        }
                        else{
                            cout<<vertex1<<" ";
                        }
                    }
                    cout<<endl;
                }
                else{
                    for(int i=1;i<=m;i++){
                        if(i%2==1){
                            cout<<vertex2<<" ";
                        }
                        else{
                            cout<<vertex1<<" ";
                        }
                    }
                    cout<<vertex1<<" ";
                    for(int i=1;i<=m;i++){
                        if(i%2==1){
                            cout<<vertex3<<" ";
                        }
                        else{
                            cout<<vertex1<<" ";
                        }
                    }
                    cout<<endl;
                }
            }
        }
    }
    return 0;
}