Give the output of the following recursive function

int compute$($string s$)$

$\{$

if $($s$.$length$()==0)$

return $0$;

else

return compute$($s$.$substr$(1))+1$;

$\}$

int main$()$

$\{$

string course $="$CSC$335"$;

cout $<<$

compute$($course$)<<$ endl;

system$("$pause$")$;

return $0$;

$\}$