Python

val $=$ Get next input

$xxx$

While val is not $-1$

YYY

val $=$ Get next input

Put sum to output

For the given pseudocode, which $xxx$ and $YYY$ will output the sum of the input integers $($stopping when $-1$ is input$)?$ Choices are in the form XXX $/$ YYY$.$

sum $=$ val $/$ sum $=$ val

sum $=$val $/$ sum $=$ sum $+$val

sum $=0/$ sum $=$ sum $+$ val

sum $=0/$ sum $=$ val