def is_prime(n):
    if n == 1:
        return False
    elif n == 2:
        return True
    else:
        for x in range(2, n):
            if n % x == 0:
                return False
        return True
filename = 'lk_text.txt'
with open(filename, "r") as ins:
    array = []
    for line in ins:
        array.append(line)
newArray = []
for i in array:
    j = i.split(' ')
    k = [int(n) for n in j]
    newArray.append(k)
SUM = 0
b = 0
for i in range(len(newArray)):
    max_n = 0
    a = b
    for j in range(len(newArray[i])):
        if newArray[i][j] > max_n:
            if not(is_prime(newArray[i][j])):
                if a == j or a+1 == j:
                    max_n = newArray[i][j]
                    b = j
    SUM += max_n
print(SUM)