question $=$ input$("$Do you want to do more calculations? yes$/$no:$")$

if question $==$ "yes":

main$()$

elif question $=="$no$"$:

print$("$Thank you and have a great day! :$-)")$

break

else:

print$("$Please enter yes or no$.")$question $=$ input$("$Do you want to do more calculations? yes$/$no:$")$

if question $==$ "yes":

main$()$

elif question $=="$no$"$:

print$("$Thank you and have a great day! :$-)")$

break

else:

print$("$Please enter yes or no$.")$