class Euler37 {

    private static class Options {
        boolean runCheckpoints = true;
    }

    private static boolean parseArguments(String[] args, Options options) {
        for (String arg : args) {
            if ("--skip-checkpoints".equals(arg)) {
                options.runCheckpoints = false;
                continue;
            }
            System.err.println("Unknown argument: " + arg);
            return false;
        }
        return true;
    }

    private static boolean isPrime(int n) {
        if (n < 2) {
            return false;
        }
        if ((n % 2) == 0) {
            return n == 2;
        }
        for (int p = 3; p <= n / p; p += 2) {
            if ((n % p) == 0) {
                return false;
            }
        }
        return true;
    }

    private static boolean isTruncatablePrime(int n) {
        if (n < 10 || !isPrime(n)) {
            return false;
        }

        String s = Integer.toString(n);
        for (int cut = 1; cut < s.length(); ++cut) {
            int left = Integer.parseInt(s.substring(cut));
            int right = Integer.parseInt(s.substring(0, s.length() - cut));
            if (!isPrime(left) || !isPrime(right)) {
                return false;
            }
        }

        return true;
    }

    private static int solve() {
        int count = 0;
        int total = 0;

        for (int n = 11; count < 11; n += 2) {
            if (isTruncatablePrime(n)) {
                total += n;
                ++count;
            }
        }

        return total;
    }

    private static boolean runCheckpoints() {
        if (!isTruncatablePrime(3797)) {
            System.err.println("Checkpoint failed for 3797");
            return false;
        }
        if (isTruncatablePrime(47)) {
            System.err.println("Checkpoint failed for 47");
            return false;
        }
        return true;
    }

    public static void main(String[] args) {
        Options options = new Options();
        if (!parseArguments(args, options)) {
            System.exit(1);
        }
        if (options.runCheckpoints && !runCheckpoints()) {
            System.exit(2);
        }

        System.out.println(solve());
    }
}