Multi Requirements: All tasks must be written in JavaScript. You can only use

Primary test

1. 
   You get necessary to acquainted with the requirements
   
2. 
   Solve the problem of "multi"
   

Requirements:
All tasks must be written in JavaScript. You can only use following native operators in our examples and you cannot initialize any extra variables.

(a + b), (a - b)	arithmetic operations
(a > b), (a < b), (a == b)	comparison operations
(a && b), (a || b), (!a)	logical operations
if (predicate){ thenBody } else {elseBody}	conditional operation
function (spec) {body}	defining custom functions

Don’t use loops, switch or any other JavaScript operators, also functions and plugins
Example-1.
function sign(n){
if (n > 0) return 1;
else return -1;
}

• 
  sign(2)
  

1

• 
  sign(-5)
  

-1
Example-2. (n > 1) The sum of numbers from 1 to n
function sum(n) {
if (n == 1) return 1;
else sum(n - 1) + n;
}

• 
  sum(4) => 10
  

Evaluation:
((sum(3) + 4)
((sum(2) + 3) + 4)
((sum(1) + 2) + 3) + 4)
((1 + 2) + 3) + 4)
((3 + 3) + 4)
(6 + 4) => 10


Task:
Write a function of multiplication (*).
Input: a and b are any positive integers
Output: only one positive integer
function multi(a, b) {
…
}

• 
  multi(3, 4)
  

12