@Override
    public String solution() {
        int count = 0;
        int sum = 0;
        
        for (int i = 11; ; i+=2) {
            if(EulerFunction.isPrime(i) && rightToLeftPrime(i) && leftToRightPrime(i)) {
                count++;
                sum += i;
            }
            if (count == 11) {
                break;
            }
        }
        return "" + sum;
    }