211013

tomatobox = [] findlist = [] countday = 0 f = 0 r = 0 start = 0 xnum, ynum = map(int, input().split()) x = [-1]*(xnum+2) tomatobox.append(x) for i in range(ynum): # 토마토 박스 만들귀 a = [] a.append(-1) data = list(map(int, input().split())) for x in range(len(data)): a.append(data[x]) a.append(-1) tomatobox.append(a) x = [-1]*(xnum+2) tomatobox.append(x) def findone(): # 숫자 1의 좌표값 찾기 global findlist global f findlist = [] for y in range(1, ynum+2): for x in range(1, xnum+2): if tomatobox[y][x] == 1: onenum = [y, x] findlist.append(onenum) f += 1 def findunripe(num): global f print(num) x = num[0] y = num[1] # print(tomatobox[x+1][y]) # print(tomatobox[x-1][y]) # print(tomatobox[x][y+1]) # print(tomatobox[x][y-1]) if (tomatobox[x+1][y] == 0): tomatobox[x+1][y] = 1 findlist.append([x+1, y]) f += 1 if (tomatobox[x-1][y] == 0): tomatobox[x-1][y] = 1 findlist.append([x-1, y]) f += 1 if (tomatobox[x][y+1] == 0): tomatobox[x][y+1] = 1 findlist.append([x, y+1]) f += 1 if (tomatobox[x][y-1] == 0): tomatobox[x][y-1] = 1 findlist.append([x, y-1]) f += 1 # def ripe(): # global countday # global r # global start # global f # start = f # for i in range(start, f): # countday += 1 # findunripe(i) # findlist[r] = 0 # r = start # print(countday-1) def cantripe(): for y in range(1, ynum + 2): for x in range(1, xnum + 2): if tomatobox[y][x] == 0: return True isallripe = False def allripe(): global isallripe for y in range(1, ynum + 2): for x in range(1, xnum + 2): if tomatobox[y][x] == 1 or tomatobox[y][x] == -1: isallripe = True else: return False return isallripe findone() if allripe(): print(0) else: while f != r: start = r for i in range(start, f): countday += 1 findunripe(findlist[r]) findlist[r] = 0 r += 1 r = start print(tomatobox) if cantripe(): print(-1) else: print(countday-1)