T=int(input())
def dfs(line,col,num):
    vis_num.append(lis[line][col])
    visit[line][col]=1
    mi=[]
    if line>0 and visit[line-1][col]==0 and lis[line-1][col]>num:mi.append(lis[line-1][col])
    if line<L-1 and visit[line+1][col]==0 and lis[line+1][col]>num:mi.append(lis[line+1][col])
    if col>0 and visit[line][col-1]==0 and lis[line][col-1]>num:mi.append(lis[line][col-1])
    if col<c-1 and visit[line][col+1]==0 and lis[line][col+1]>num:mi.append(lis[line][col+1])
    if len(mi)>0:
        n=min(mi)
        for g in range(L):
            for h in range(c):
                if lis[g][h]==n:dfs(g,h,num+1)
    else:return
for i in range(T):
    lis=[]
    vis_num=[]
    visit=[]
    al=input().split()
    L,c=int(al[0]),int(al[1])
    for i in range(L):
        bl=input().split()
        small=[]
        for j in bl:
            try:small.append(int(j))
            except:pass
        lis.append(small)
        zero=[]
        for b in range(len(small)):zero.append(0)
        visit.append(zero)
    dfs(0,0,0)
    print(len(vis_num))
    for i in vis_num:print(i,end=" ")
    print()