Yeon-seok ran 18 meters (m) today. If he doubles his distance each day, find how many meters (m) he would run on the fourth day.
18 2 4 1 [OP_SUB] [OP_POW] [OP_MUL]
var_a = 18
var_b = 2
var_c = 4
var_d = 1
var_e = var_c - var_d
var_f = var_b ** var_e
var_g = var_a * var_f
print(int(var_g))