Eunji ate 9 of the tangerines in the basket, and her mother put 5 more tangerines in the basket, and the number of tangerines in the basket increased to 20. How many tangerines were in the first basket?
20 9 [OP_ADD] 5 [OP_SUB]
var_a = 20
var_b = 9
var_c = var_a + var_b
var_d = 5
var_e = var_c - var_d
print(int(var_e))