def min_sum_path(A): 
	memo = [None] * len(A) 
	n = len(A) - 1
	for i in range(len(A[n])): 
		memo[i] = A[n][i] 
	for i in range(len(A) - 2, -1,-1): 
		for j in range( len(A[i])): 
			memo[j] = A[i][j] + min(memo[j], 
									memo[j + 1]) 
	return memo[0]