Yoojung gave 7 candies to her older sister and 6 to her younger sister, and there were 15 left over. How many candies did Yoojung have at first?
15 7 [OP_ADD] 6 [OP_ADD]
var_a = 15
var_b = 7
var_c = var_a + var_b
var_d = 6
var_e = var_c + var_d
print(int(var_e))