Why this output

Question

After i run main i get weird output , Why?

https://sololearn.com/compiler-playground/c79aLq16PNS2/?ref=app
https://sololearn.com/compiler-playground/c5ChlTAxZiZ3/?ref=app
https://sololearn.com/compiler-playground/c33GgxURKH5K/?ref=app
https://sololearn.com/compiler-playground/cv6tr7ziGu67/?ref=app
https://sololearn.com/compiler-playground/cn579bwqJZF2/?ref=app

output:
home/ ~$ ./a.out

Appending: the a

Appending: au�

Appending: sour