If the lengths of the two sides of a rectangle are 9 centimeters (cm) and 11 centimeters (cm), find the sum of the lengths of the four sides.
9 11 [OP_ADD] 2 [OP_MUL]
var_a = 9
var_b = 11
var_c = var_a + var_b
var_d = 2
var_e = var_c * var_d
print(int(var_e))