def solution(triangle):
    for i in range(len(triangle) -1 ) :
        triangle[i+1][0] += triangle[i][0]
        triangle[i+1][-1] += triangle[i][-1]
    
    for i in range(2, len(triangle)) :
        for j in range(1, len(triangle[i]) -1) :
            triangle[i][j] += max(triangle[i-1][j-1], triangle[i-1][j])
    return  max(triangle[-1])