There are 11 ripe watermelons and 13 unripe watermelons. If 15 of these watermelons are seedless, how many watermelons have seeds?
11 13 [OP_ADD] 15 [OP_SUB]
var_a = 11
var_b = 13
var_c = var_a + var_b
var_d = 15
var_e = var_c - var_d
print(int(var_e))