def main():
    S = input()
    east_win = 0
    west_win = 0
    for result in S:
        match result:
            case "X":
                east_win = 0
                west_win += 1
            case "O":
                east_win += 1
                west_win = 0

        if east_win >= 3:
            print("East")
            return

        if west_win >= 3:
            print("West")
            return

    print("NA")


if __name__ == "__main__":
    main()