COMP2041

21T2 Q2 — 男生姓氏（Shell 管道）

stdin 给出选课数据，格式 课程|学号|姓名|计划|性别（姓名为 姓, 名，性别 M/F）。写一条单一 Shell 管道，输出男生的姓，每个姓只出现一次，按字母序排列。输入是无序的。

示例见上。

POSIX shell only (#!/bin/dash); standard UNIX filters; no awk, Perl, C or Python. From COMP2041/9044 21T2 Final.

样例

stdin

COMP1511|3360379|Costner, Kevin Augustus |3978/1|M
COMP1511|3364562|Carey, Mary |3711/1|M
COMP3311|3383025|Thorpe, Ian Augustus |3978/3|M
COMP4920|3860448|Steenburgen, Mary Nell |3978/3|F
COMP1521|3360582|Neeson, Liam |3711/2|M
COMP3411|3863711|Klum, Heidi June Anne |3978/3|F
COMP3141|3383025|Thorpe, Ian Augustus |3978/3|M
COMP3891|3863711|Klum, Heidi June Anne |3978/3|F
COMP3331|3383025|Thorpe, Ian Augustus |3978/3|M
COMP2041|3860448|Steenburgen, Mary Nell |3978/3|F
COMP2041|3360582|Neeson, Liam |3711/2|M
COMP3311|3711611|Klum, Mary |3978/3|F
COMP3311|3371161|Thorpe, Ian Fredrick |3711/3|M
COMP3331|5122456|Wang, Wei |3978/2|M
COMP3331|5456732|Wang, Wei |3648/3|M
COMP4920|5456732|Wang, Wei |3648/3|M

期望输出

Carey
Costner
Neeson
Thorpe
Wang

shell