Between a certain natural number and 81, there are 15 consecutive natural numbers. What is this certain number if it is a natural number less than 81?
81 15 [OP_SUB] 1 [OP_SUB]
var_a = 81
var_b = 15
var_c = var_a - var_b
var_d = 1
var_e = var_c - var_d
print(int(var_e))