Yoongi, Eunji, and Yuna have several books. If Yoongi gives 5 books to Eunji, Eunji gives 10 books to Yuna, and Yuna gives 15 books to Yoongi, all three of them will have 45 books each. How many books did Yoongi have at first?
45 15 [OP_SUB] 5 [OP_ADD]
var_a = 45
var_b = 15
var_c = var_a - var_b
var_d = 5
var_e = var_c + var_d
print(int(var_e))