What weight pencil is recommended for darkening lines and for lettering? *

While the softer B pencils are generally considered the best for shading, there's no reason to discount the harder H pencils. The HB and H are good choices for fine, light, even shading. However, they too have drawbacks. Pencil grades from HB through H, 2H to 5H get progressively harder and are easier to keep sharp.

get int input for a

get int input for b

get string input for operator

if a is not int or b is not int throw exception and print error

if operator is not * / // or % throw exception and print error

if operator is * do multiplication of a and b and make answer c

else if operator is / do division of a and b and make answer c

else if operator is // do floor division of a and b and make answer c

else if operator is % do floor modulo of a and b and make answer c

print c