--description--

The number 3797 has an interesting property. Being prime itself, it is possible to continuously remove digits from left to right, and remain prime at each stage: 3797, 797, 97, and 7. Similarly we can work from right to left: 3797, 379, 37, and 3.

Find the sum of the only n (8 ≤ n ≤ 11) primes that are both truncatable from left to right and right to left.

NOTE: 2, 3, 5, and 7 are not considered to be truncatable primes.

--hints--

truncatablePrimes(8) should return a number.

assert(typeof truncatablePrimes(8) === 'number');

truncatablePrimes(8) should return 1986.

assert(truncatablePrimes(8) == 1986);

truncatablePrimes(9) should return 5123.

assert(truncatablePrimes(9) == 5123);

truncatablePrimes(10) should return 8920.

assert(truncatablePrimes(10) == 8920);

truncatablePrimes(11) should return 748317.

assert(truncatablePrimes(11) == 748317);

--seed--

--seed-contents--

function truncatablePrimes(n) {

  return n;
}

truncatablePrimes(11);

--solutions--

// solution required