using System;

public class PyramidSlideDown
{
    public static int LongestSlideDown(int[][] pyramid)
    {
      for (var i = pyramid.GetLength(0) - 2; i >= 0; i--) {
        for (var j = 0; j <= i; j++) {
          if (pyramid[i + 1][j] > pyramid[i + 1][j + 1]) {
            pyramid[i][j] += pyramid[i + 1][j];
          } else {
            pyramid[i][j] += pyramid[i + 1][j + 1];
          }
        }
      }

      return pyramid[0][0];
    }
}