Write an algorithm to input a number and find its square root if it is

positive and power $2$ in case of negative.

$2.$ Write an algorithm to input a number and find its power $2$ if it

belongs to $[0,5],$ square root if it is greater than $5$ and no change in

case of negative.

$3.$ Write an algorithm to solve the first order equation.

$4.$ Write an algorithm to calculate sum of all even numbers from $1$ to n$,$ n

is optional.