function solution(numbers, hand) {
    
    const numToPos = number => {
        if(number === 0){
            return [1,3]
        } 
        
        const x = (number -1) % 3
        const y = Math.floor((number-1) / 3)
        
        return [x,y]
    }
    
    const cost = (pos1, pos2) => Math.abs(pos1[0] - pos2[0]) + Math.abs(pos1[1] - pos2[1])

    const current = {
        left: [0,3],
        right: [2,3]
    }
    
    const acronyms = {
        left: "L",
        right: "R",
    }
    
    return numbers.map(number => {
        const newPos = numToPos(number)
        
        if(newPos[0] === 2){
            current.right = newPos
            return acronyms.right
        }
        
        if(newPos[0] === 0){
            current.left = newPos
            return acronyms.left
        }
        
        const leftCost = cost(newPos, current.left)
        const rightCost = cost(newPos, current.right)    
        
        const movedHand = leftCost > rightCost ? 'right' : leftCost < rightCost ? 'left' : hand
        current[movedHand] = newPos
        
        return acronyms[movedHand]
    }).join('')
}