# Enter your code here. Read input from STDIN. Print output to STDOUT
def is_prime(n):
    if n < 2:
        return False
    for i in range(2, int(n**0.5) + 1):
        if n % i == 0:
            return False
    return True

def is_truncatable(n):
    s = str(n)
    for i in range(1, len(s)):
        if not is_prime(int(s[i:])) or not is_prime(int(s[:i])):
            return False
    return True

limit = int(input())
trunc_primes = []
for p in range(10, limit):
    if is_prime(p) and is_truncatable(p):
        trunc_primes.append(p)
print(sum(trunc_primes))