BUUCTF: Missing through time and space

Subject address: https://buuoj.cn/challenges#%E7%A9%BF%E8%B6%8A%E6%97%B6%E7%A9%BA%E7%9A%84%E6%80%9D% E5%BF%B5

MP3 files, it is clear that they are Morse Code
Morse Code Online: http://www.zhongguosou.com/zonghe/moersicodeconverter.aspx

Audacityturn on

First paragraph

..-. ----- ..--- ----. -... -.. -.... ..-. ..... ..... .---- .---- ...-- ----. . . -.. . -... ---.. . ....- ..... .- .---- --... ..... -... ----- --... ---.. -....

After Morse code conversion

F029BD6F551139EEDEB8E45A175B0786

Second paragraph

..-. ----- ..--- ----. -... -.. -.... ..-. .....

F029BD6F5

It is the same as the beginning of the first paragraph, the flag is only the first paragraph, change the case

PS C:\Users\Administrator> php -r "var_dump(strtolower('F029BD6F551139EEDEB8E45A175B0786'));"
string(32) "f029bd6f551139eedeb8e45a175b0786"

flag{
    
    f029bd6f551139eedeb8e45a175b0786}