function sumOf(input){ let firstNum=Number(input.shift()); let secondNum=Number(input.shift()); let line=""; for (let i=firstNum; i<=secondNum; i++){ let strNum=i+""; let leftSum=Number(strNum.charAt(0))+ Number(strNum.charAt(1)); let rightSum=Number(strNum.charAt(3))+ Number(strNum.charAt(4)); if (leftSum