A = [12, 16, 20, 18, 13, 52, 67, 66]
dima = 0
for vova in range(len(A)):
    if A[vova] % 3 == 0 :
        dima += 1
for vova in range(len(A)):
    if A[vova] % 3 != 0 :
        A[vova] -= dima
print(A)