18

let arr = [
  [75],
  [95,64],
  [17,47,82],
  [18,35,87,10],
  [20,04,82,47,65],
  [19,01,23,75,03,34],
  [88,02,77,73,07,63,67],
  [99,65,04,28,06,16,70,92],
  [41,41,26,56,83,40,80,70,33],
  [41,48,72,33,47,32,37,16,94,29],
  [53,71,44,65,25,43,91,52,97,51,14],
  [70,11,33,28,77,73,17,78,39,68,17,57],
  [91,71,52,38,17,14,91,43,58,50,27,29,48],
  [63,66,04,68,89,53,67,30,73,16,69,87,40,31],
  [04,62,98,27,23,09,70,98,73,93,38,53,60,04,23]
];

let dp = new Array(15).fill(0);
let prevDP = new Array(15).fill(0);
prevDP[0] = arr[0][0];

for(let A = 1; A<arr.length; A++){
    for(let I = 0; I<arr[A].length; I++){
        dp[I] = arr[A][I] + Math.max(prevDP[I-1]??0, prevDP[I]??0 );
    }
    prevDP = [...dp];
}

console.log( Math.max(...dp) );