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function getPatternSum(arr, i, j) {
  return (
    arr[i][j] + arr[i][j + 1] + arr[i][j + 2] +
            arr[i + 1][j + 1] +
arr[i + 2][j] + arr[i + 2][j + 1] + arr[i + 2][j + 2]
  )
}

function getSummedMatrix(arr) {
  let summedOuterArr = [] 
  for (let i = 0; i <= arr.length - 3; i++) {
    let summedInnerArray = [] 
    for (let j = 0; j <= arr[i].length - 3; j++) {
      summedInnerArray.push(getPatternSum(arr, i, j)) 
    }
    summedOuterArr.push(summedInnerArray)
  }
  return summedOuterArr
}

function findBiggestNumberOf2DMatrix(arr) {
  let theBiggest
  arr.forEach((innerArr) => {
    innerArr.forEach((i) => {
      theBiggest = !theBiggest || theBiggest < i ? i : theBiggest
    })
  })
  return theBiggest
}

function calculateTheBiggestSum(arr) {
  const sums = getSummedMatrix(arr)
  const theBiggestSum = findBiggestNumberOf2DMatrix(sums)
  return theBiggestSum
}