There are 3 watermelons and 7 apples. How many melons are there when the number of melons is twice the sum of the number of watermelons and apples?
3 7 [OP_ADD] 2 [OP_MUL]
var_a = 3
var_b = 7
var_c = var_a + var_b
var_d = 2
var_e = var_c * var_d
print(int(var_e))