def notPrime(num):
    for i in range(2,num):
        if num % i == 0:
            return True
    return False



def maxPathSum(pyramid, m, n):
    for i in range(m-1, -1, -1):
        for j in range(i+1):
            if (notPrime(pyramid[i+1][j]) and notPrime(pyramid[i+1][j+1])) and (notPrime(pyramid[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]
            else:
                if not (notPrime(pyramid[i+1][j])) and notPrime(pyramid[i+1][j+1]):
                    pyramid[i][j] += pyramid[i+1][j+1]
                elif not (notPrime(pyramid[i+1][j+1])) and notPrime(pyramid[i+1][j]):
                    pyramid[i][j] += pyramid[i+1][j]
                else:
                    continue
    
    return pyramid[0][0]


file = open("test.txt","r")
pyramid = []
count = 0
while True:
    data = file.readline().split()
    if not data:
        file.close()
        break
    pyramid.append(data)
for row in pyramid:
    for i in range(len(row)):
        row[i] = int(row[i])
for row in pyramid:    
    for num in range(len(pyramid[-1])-len(row)):
        row.append(0)
len_row = int(len(pyramid))
len_col = int(len(pyramid[0]))
print(maxPathSum(pyramid,len_row -1 ,len_col -1))