What is the output of the following program fragment?

int num$1=10$;

int num$2=20$;

int sum $=$ num$1+$ num$2$;

cout $<<$ num$1<<"+"<<$ num$2<<"="<<$ sum $<<$ endl;

num$1+$num$2=$sum

$10+20=30$

num$1+$ num$2=$ sum

$10+20=30$