Straight/Flush Probability Question

[RocketManJames]

Just had a random thought the other night, and I'm now curious to know the answer.

Standard deck of cards has 13 values and 4 suits. Flushes are rarer than straights given 5 cards.

If we had a deck of cards with N values and S suits... what would N and S have to be such that the probability of getting a flush is equal to that of getting a straight given 5 cards.

Anyone know the method to solve this? Are there multiple answers?

-RMJ