class Euler46 {

    private static class Options {
        boolean runCheckpoints = true;
    }

    private static boolean parseArguments(String[] args, Options options) {
        for (int i = 0; i < args.length; ++i) {
            String arg = args[i];
            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 canBeWritten(int n) {
        for (int s = 1; 2 * s * s < n; ++s) {
            int candidate = n - 2 * s * s;
            if (isPrime(candidate)) {
                return true;
            }
        }
        return false;
    }

    private static int solve() {
        for (int n = 9; ; n += 2) {
            if (isPrime(n)) {
                continue;
            }
            if (!canBeWritten(n)) {
                return n;
            }
        }
    }

    private static boolean runCheckpoints() {
        if (!canBeWritten(33)) {
            System.err.println("Checkpoint failed for 33");
            return false;
        }
        if (!canBeWritten(45)) {
            System.err.println("Checkpoint failed for 45");
            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());
    }
}