Baekjoon-15683-감시

N,M = map(int,input().split())
cctvs,board = [],[]
total_blind = 0
for n in range(N):
    line = list(map(int,input().split()))
    board.append(line)
    for m in range(M):
        if 0<line[m]<6:
            cctvs.append([line[m],n,m])
        if line[m]==0:
            total_blind += 1

directions = [[1,0],[0,1],[-1,0],[0,-1]]
cctv_types = {
    1: [[0],[1],[2],[3]],
    2: [[0,2],[1,3]],
    3: [[0,1],[1,2],[2,3],[3,0]],
    4: [[0,1,2],[1,2,3],[2,3,0],[3,0,1]],
    5: [[0,1,2,3]]
}
for cctv_type, idxs in cctv_types.items():
    cctv_types[cctv_type] = [[directions[i] for i in idx] for idx in idxs]

# O(4^8)=O(2^16) 충분
answer = M*N
def dfs(depth):
    global answer
    if depth == len(cctvs):
        count = 0
        for line in board:
            for i in line:
                if i == 0:
                    count += 1
        if answer > count:
            answer = count
            # print('-----%d------'%answer)
            # print(*board,sep='\n')
        return
    else:
        t,x,y = cctvs[depth]
        for dirs in cctv_types[t]:
            visited = []
            for dx,dy in dirs:
                nx,ny = x,y
                while True:
                    nx += dx
                    ny += dy
                    if 0<=nx<N and 0<=ny<M:
                        if board[nx][ny] == 6:
                            break
                        elif board[nx][ny] == 0:
                            visited.append([nx,ny])
                            board[nx][ny] = 7
                    else:
                        break
            dfs(depth+1)
            for nx,ny in visited:
                board[nx][ny] = 0

dfs(0)
print(answer)