// Accepts a number x as input and returns its square

var square = function (x) {

return x * x;

};

// Write the function multiply below

// It should take two parameters and return the product

var multiply = function (z , y) {

if(z==0 || y==0){

return 0;

} else {

return z + y;

}

};

multiply(2 , 3);

it says

Oops, try again. Your function multiply failed on inputs 1,1 where you returned 2 instead of 1

how is it possible? 1+1=2, is it?