$\%$ Do not modify CalculateSum

function maxSum $=$ CalculateSum$($userNum$1,$ userNum$2,$ userNum$3)$

maxSum $=$ MaxValue$($userNum$1,$ userNum$2)+$ userNum$3$;

end

$\%$ Define a function MaxValue that returns the largest input value

$\%$ Function inputs: numA, numB

$\%$ Function output: maxNum

$\%$ function maxNum $...$