#include <bits/stdc++.h>
using namespace std;
#ifndef _LOCAL
//#pragma GCC optimize("O3,Ofast")
#else
#pragma GCC optimize("O0")
#endif
template<typename t> inline void umin(t &a, const t b) {a = min(a, b);}
template<typename t> inline void umax(t &a, const t b) {a = max(a, b);}
typedef pair<int, int> pii;
typedef long long ll;
typedef long double ld;
typedef int8_t byte;
ll time() {return chrono::system_clock().now().time_since_epoch().count();}
mt19937 rnd(time());
#define ft first
#define sd second
#define len(f) int((f).size())
#define bnd(f) (f).begin(), (f).end()
#define _ <<' '<<
const int inf = 1e9 + 5;
const ll inf64 = 4e18 + 5;
const int md = 998244353;
namespace MD {
void add(int &a, const int b) {if((a += b) >= md) a -= md;}
void sub(int &a, const int b) {if((a -= b) < 0) a += md;}
int prod(const int a, const int b) {return ll(a) * b % md;}
};
const int N = 1e3 + 5;
const int NN = 2e3 + 5;
int n, m, nn, mm;
typedef array<array<int, NN>, NN> mt;
mt a[11], A, z;
void combine(mt &a, mt &b, mt &c, int dx, int dy) {
vector<pii> f;
for(int i = 0; i + dx < nn; ++i)
for(int j = 0; j + dy < mm; ++j)
f.push_back({i, j});
sort(bnd(f), [&] (const pii &l, const pii &r) {
int &lfi = a[l.ft][l.sd], &lse = b[l.ft + dx][l.sd + dy];
int &rfi = a[r.ft][r.sd], &rse = b[r.ft + dx][r.sd + dy];
return lfi == rfi ? lse < rse : lfi < rfi;
});
vector<int> e(len(f));
for(int i = 0, j = 0; i < len(f); ++i) {
j += i && (a[f[i - 1].ft] [f[i - 1].sd] != a[f[i].ft] [f[i].sd] ||
b[f[i - 1].ft + dx][f[i - 1].sd + dy] != b[f[i].ft + dx][f[i].sd + dy]);
e[i] = j;
}
for(int i = 0; i < len(f); ++i)
c[f[i].ft][f[i].sd] = e[i];
}
void solve() {
cin >> n >> m;
for(int i = 0; i < n + n; ++i) {
for(int j = 0; j < m + m; ++j) {
if(i < n && j < m) {
char c; cin >> c;
a[0][i][j] = c == '.';
} else
a[0][i][j] = a[0][i % n][j % m];
A[i][j] = 0;
}
}
z = a[0];
nn = n << 1;
mm = m << 1;
for(int i = 0, u = m; ; ++i) {
if(i) combine(a[i - 1], a[i - 1], a[i], 0, 1 << i - 1);
if(u & 1 << i) {
combine(a[i], A, A, 0, 1 << i);
u ^= 1 << i;
if(!u) break;
}
}
a[0] = A;
for(int i = 0; i < nn; ++i)
for(int j = 0; j < mm; ++j)
A[i][j] = 0;
for(int i = 0, u = n; ; ++i) {
if(i) combine(a[i - 1], a[i - 1], a[i], 1 << i - 1, 0);
if(u & 1 << i) {
combine(a[i], A, A, 1 << i, 0);
u ^= 1 << i;
if(!u) break;
}
}
int x = 0, y = 0;
for(int i = 0; i < n; ++i)
for(int j = 0; j < m; ++j)
if(A[i][j] < A[x][y])
x = i, y = j;
for(int i = 0; i < n; ++i, cout << '\n')
for(int j = 0; j < m; ++j) cout << (z[x + i][y + j] ? '.' : '*');
}
signed main() {
ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#ifndef _LOCAL
// freopen("file.in", "r", stdin);
// freopen("file.out", "w", stdout);
#else
system("color a");
freopen("in.txt", "r", stdin);
int t; cin >> t;
while(t--)
#endif
solve();
}
