Find the number of natural numbers among 1 to 30 that are not odd.
1 30 1 [OP_LIST_ARANGE] 1 30 [OP_LIST_ODD] [OP_SET_DIFFERENCE] [OP_LIST_LEN]
var_a = 1
var_b = 30
var_c = 1
list_a = [i for i in range(var_a, var_b + 1, var_c)]
var_d = 1
var_e = 30
list_b = []
if var_d%2==0:
    for i in range(var_d+1, var_e+1, 2):
        list_b.append(i)
else:
    for i in range(var_d, var_e+1, 2):
        list_b.append(i)
list_c = list(set(list_a) - set(list_b))
var_f = len(list_c)
print(int(var_f))