60

False
                else:
                    ark[y] = -1
            else:
                if ark[y] == -1:
                    t = False
                else:
                    ark[y] = 1
for x in range(8):
    for y in range(1, 8):
        if qwe[y][x] == qwe[y-1][x]:
            if qwe[y][x] < 0:
                if ark[y] == 1 or ark[y-1] == 1:
                    t = False
                else:
                    ark[y] = -1
                    ark[y-1] = -1
            else:
                if ark[y] == -1 or ark[y-1] == -1:
                    t = False
                else:
                    ark[y] = 1
                    ark[y-1] = 1
for x in range(8):
    for y in range(1, 8):
        if abs(qwe[y][x]) == abs(qwe[y-1][x]) and qwe[y][x] != qwe[y-1][x]:
            if ark[y] == ark[y-1] and ark[y] + ark[y-1] != 0:
                t = False
if t:
    print('YES')
else:
    print('NO')