# JOMO 7, Short 4

Trevor creates a infinite sequence $$\mathrm{S}$$ of integers by repeatedly adding the digits $$2,0,1$$ and $$3$$ to the end of the previous number. For example, the first few numbers he creates are $$2, 20, 201, 2013, 20132, 201320, 2013201 \ldots$$

Find the number of primes in $$\mathrm{S}$$.

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