automaton – It's $ {w in {a, b } ^ * | text {the product of the number from $ to $ & # 39; s and the number of $ b $ & # 39; Is it an odd number} } $ regular?

It is the next language $$ {w in {a, b } ^ * | text {the product of the amount of $ to $ & # 39; s and the amount of $ b $ & # 39; s is an odd number} } $$ regular?

If I'm not wrong, the condition is the same as having an odd number of $ a $& # 39; s and an odd number of $ b $& # 39; s I have tried to use the Pumping Motto without success. So I'm suspecting that it's regular. But I can not think of a regular expression or an automaton that accepts it.

Any help would be appreciated.