# Problem 51: Prime digit replacements

By replacing the 1st digit of the 2-digit number \*3, it turns out that
six of the nine possible values: 13, 23, 43, 53, 73, and 83, are all
prime. By replacing the 3rd and 4th digits of 56\*\*3 with the same
digit, this 5-digit number is the first example having seven primes
among the ten generated numbers, yielding the family: 56003, 56113,
56333, 56443, 56663, 56773, and 56993. Consequently 56003, being the
first member of this family, is the smallest prime with this property.
Find the smallest prime which, by replacing part of the number (not
necessarily adjacent digits) with the same digit, is part of an eight
prime value family.