What is the total number of vertices of a figure with 21 edges, 9 faces, and two polygonal base sides that are parallel and congruent?
21 3 [OP_DIV] 2 [OP_MUL]
var_a = 21
var_b = 3
var_c = var_a / var_b
var_d = 2
var_e = var_c * var_d
print(int(var_e))