import sys
def isPrime(num):
        if num == 1:
                return False
        for i in range(2, num):
                if num % i == 0:
                        return False
        return True

def maxSum(tri, i, j, size):
        if(i == size ):
          return 0
        res = tri[i][j]
        res += max(maxSum(tri, i + 1, j, size), maxSum(tri, i + 1, j + 1, size))
        return res

f = open("/content/drive/My Drive/input.txt","r")
text = f.read()
rows = text.split('\n')
pyramid = []

for row in rows:
        currentRow = row.split(' ')
        pyramid.append(currentRow)
for row in pyramid:
    for i in range(len(row)):
        row[i] = int(row[i])
for row in pyramid:    
    for i in range(len(pyramid[-1])-len(row)):
        row.append(0)
for i in range(len(pyramid)):
    for j in range(len(pyramid)):
        if isPrime(pyramid[i][j]):
            pyramid[i][j] = -sys.maxsize - 1 
            #to eliminate prime numbers, I assign max negative value to those cells

print("The maximum sum is ", maxSum(pyramid, 0, 0, len(pyramid)))