What is the command to replace blocks in Minecraft PE?
I want to replace grey wool blocks with grey concrete
I have tried so many commands but none seem to work!

Write a function called checkfactor that takes two arrays of positive numbers, firstnumberrow and secondnumberrow. checkfactor checks if the first entry in firstnumberrow is divisible by the first entry in secondnumberrow, and performs the same operation on the next array elements until all entries have been checked. all the numbers are positive and the number of entries in the arrays are the same. the function should return the identified divisible numbers in two row arrays named firstdivisible and seconddivisible.restrictions: branches or loops should not be used. the code must use the internal mod and logical functions.hint: the mod function should be used to determine if two numbers are divisible. ex: for num1 and num2 if mod(num1,num2) is 0, then the two numbers are divisible.this is matlab