Mary is a teacher in a middle school and she has a table seat storing students' names and their corresponding seat ids.

The column id is continuous increment.

Mary wants to change seats for the adjacent students.

Can you write a SQL query to output the result for Mary?

+---------+---------+

|    id   | student |

+---------+---------+

|    1    | Abbot   |

|    2    | Doris   |

|    3    | Emerson |

|    4    | Green   |

|    5    | Jeames  |

+---------+---------+

For the sample input, the output is:

+---------+---------+

|    id   | student |

+---------+---------+

|    1    | Doris   |

|    2    | Abbot   |

|    3    | Green   |

|    4    | Emerson |

|    5    | Jeames  |

+---------+---------+

Note:
If the number of students is odd, there is no need to change the last one's seat.

# Write your MySQL query statement below

SELECT

    s.id,

    s.student

FROM

    (

        SELECT

            id - 1 AS id,

            student

        FROM

            seat

        WHERE

            (id % 2 = 0)

        UNION

            SELECT

                (CASE WHEN (cnt%2=1) AND id=cnt THEN id ELSE id + 1 END) AS id,

                student

            FROM

                seat,

                (select count(*) as cnt from seat) as seatcnt

            WHERE

                (id % 2 = 1)

    ) s

GROUP BY

    s.id ASC