function adjacentElementsProduct(nums) {
    //  write code here.
    
    // setting variables to keep track of the value 
    let startingValue = 1;
    let maxValue = 0;
    const sumOfTwo = 2
    //adding the two first value to the starting value 
    for (let i = 0 ; i < sumOfTwo ; i++){
        
        startingValue *= nums[i];
    }
    
    maxValue = startingValue;

    for(let i = sumOfTwo; i <= nums.length - 1; i ++){
        //dividing the current value by the number it was multiply 
        // by the value at the next index         
        startingValue = startingValue / nums[i - sumOfTwo] * nums[i] ;
        maxValue = Math.max(maxValue , startingValue);
    }

    return maxValue;
}



/**
* Test Suite 
*/
describe('adjacentElementsProduct()', () => {
    it('returns largest product of adjacent values', () => {
        // arrange
        const nums = [3, 6, -2, -5, 7, 3];
        
        // act
        const result = adjacentElementsProduct(nums);

        // log
        console.log("result: ", result);
        
        // assert
        expect(result).toBe(21);
    });
});