Candidates range from 1 to 50.
50/4=12 positive integers are multiples of 4
50/6=8 positive integers are multiples of 6
50/12=4 positive integers are multiples of 12 (LCM of 4 and 6)
By the inclusion/exclusion principle, the number of multiples of either 4 or 6 is equal to 12+8-4=16.
Therefore, the complement is the number of positive integers that are multiples of neither 4 nor 6 = 50-16=34.