I need help getting started with this structural induction question

Problems Problem 1 (10 points) Consider the following inductive definition of an approved bit string of O's and 1's. Foundation: The bit string 0 is an approved bit string. Constructor: If s and t are approved bit strings, then so are 1s1 and sOt Use structural induction to show that every approved bit string consists of an odd number of O's and an even number of 1's. Make sure to indicate what P(n) is (i.e. the predicate you are proving holds true for all natural numbers n). See the Properties and Definitions page for definons and basic properties of even and odd that you may use in your proof