import itertools


def main():
    field = []
    for _ in range(3):
        field.append(input())

    dx = [1, 0, -1, 0, 1, -1, -1, 1]
    dy = [0, 1, 0, -1, 1, 1, -1, -1]
    for i, j in itertools.product(range(3), range(3)):
        for k in range(4):
            x, y = i + dx[k], j + dy[k]
            if x < 0 or x > 2 or y < 0 or y > 2:
                continue
            if field[x][y] == field[i][j]:
                print("No")
                exit()
    print("Yes")


if __name__ == "__main__":
    main()