Create a program that asks the user to enter a string.$$ Then the program output a string made up of every third character of the input string.$$ For example, if the user enters computational,$$the output from the program is the string mtia$($in a single string, and not as individual letters$).$

Hints:

Use a counter$-$controlled loop to produce the output where the counter goes up by $3.$ How can you use the length of$...$ block in the test condition to stop the loop?

Remember, you can use the letter...of$...$ block to find each of the required letters from the input string.$$ How can you use the counter variable from the loop in this block?

For each pass through the loop, use the join... block to join each letter with the string produced from the previous pass through the loop.