Consider the sequence of primes at prime positions in the sequence of primes.

3, 5, 11, 17, 31, 41, 59, 67, 83, 109...

These are the 2nd prime, the 3rd prime, the 5th prime, and so on. Call these numbers superprimes.

W, X, Y, and Z are 4 superprimes in arithmetic progression, and W<X<Y<Z. Find the smallest possible value of Z.