Geon-wu and Jia turned in opposite directions at the circular playground and met each other. If the circumference of the field is 18 kilometers (km) and Geon-wu runs at 5 kilometers (km) per hour and Jia runs at 4 kilometers (km) per hour, how far did Gern-wu run?
18 5 4 [OP_ADD] [OP_DIV] 5 [OP_MUL]
var_a = 18
var_b = 5
var_c = 4
var_d = var_b + var_c
var_e = var_a / var_d
var_f = 5
var_g = var_e * var_f
print(int(var_g))