There are three bottles, A, B, and C, each with different sizes. 7 bottles of A and 3 bottles of B have the same capacity, and 1 bottle of B and 5 bottles of C are the same. How many bottles of C are equal to 21 bottles of A?
21 7 [OP_DIV] 3 [OP_MUL] 1 [OP_DIV] 5 [OP_MUL]
var_a = 21
var_b = 7
var_c = var_a / var_b
var_d = 3
var_e = var_c * var_d
var_f = 1
var_g = var_e / var_f
var_h = 5
var_i = var_g * var_h
print(int(var_i))