The average weight of 10 watermelons is 4.2 kg. If one of these watermelons is replaced by a watermelon weighing 5 kilograms (kg), the average weight of the watermelons becomes 4.4 kilograms (kg). How many kilograms (kg) is the watermelon that has been replaced?
5 4.4 4.2 [OP_SUB] 10 [OP_MUL] [OP_SUB]
var_a = 5
var_b = 4.4
var_c = 4.2
var_d = var_b - var_c
var_e = 10
var_f = var_d * var_e
var_g = var_a - var_f
print(int(eval('{:.2f}'.format(round(var_g+1e-10,2)))))