def main$()$:

outfile $=$ open$($numbers$.$txt$,$w$)$

num$1=$ int$($input$($Enter a number: $))$

num$2=$ int$($input$($Enter another number: $))$

num$3=$ int$($input$($Enter a number: $))$

outfile.write$($str$($num$1)+$

$)$

outfile.write$($str$($num$2)+$

$)$

outfile.write$($str$($num$3)+$

$)$

outfile.close$()$

print$($Data written to numbers.txt$)$

if $\_$name$\_==\_$main$\_$:

main$()$

Explain in detail the purpose of this program, how it executes and the expected output