function solve(arr) {
  function calcSum(a, b) {
    return a + b;
  }

  let sumOfRowOne = arr[0].reduce(calcSum);
  let sumOfRowLast = arr[arr.length-1].reduce(calcSum);

  if (sumOfRowOne == sumOfRowLast) {
    let sumOfLeftCol = 0;
    let sumOfRightCol = 0;
    for (let i = 0; i < arr.length; i++) {
      sumOfLeftCol += arr[i][0];
      sumOfRightCol += arr[i][arr.length-1];

    }
    return sumOfLeftCol == sumOfRightCol &&  sumOfRightCol == sumOfRowOne ?
      true : false

} else {
    return false;
  }
}