Python || Dynamic Programming: I need help fixing my code for a make change program.

The code must be able to run on flip servers via terminal or putty. However, when I try to run the code on terminal, I keep getting the following error:

"ValueError: invalid literal for int() with base 10: '' "

Please help me fix it!

The input file I'm using is name "amount.txt":

1 2 5

10

1 3 7 12

29

1 2 4 8

15

The output file MUST produce the following output:

1 2 5

10

0 0 2

2

1 3 7 12

29

0 1 2 1

4

1 2 4 8

15

1 1 1 1

4

Code:

# make change DP algorithm

def make_change(V,A):

# array to hold how many coins were needed per element

T = [float('Inf')]*(A+1)

# with a value of 0, 0 coins are needed

T[0] = 0

# array to hold the last coin used on the corresponding T element

R = [-1]*(A+1)

# array to hold total amount of each coin used

C = [0]*len(V)

# steps through the array of coins and makes change if possible

for j in range(len(V)):

for i in range(1,A+1):

# if the number for change to be made for is greater than the

# selected coin value

if i >= V[j]:

# if the newly selected coin value plus 1 is less than the

# current coin value

if (T[i-V[j]] + 1) < T[i]:

T[i] = 1 + T[i-V[j]]

R[i] = j

# count how many coins were used per element

while A != 0:

C[R[A]] += 1

A = A - V[R[A]]

return C

# open the input file

input_file = open('amount.txt','r')

# create the output file

output_file = open('change.txt','w')

# convert the string to a array of characters

V = input_file.readline().split(' ')

# get the next line

A = input_file.readline()

while V != [''] and A != ['']:

# convert to an array of integers

V = map(int, V)

# convert the string to an int

A = int(A)

# call make_change

change = make_change(V,A)

# total number of coins

total_coins = sum(change)

# output the results to the output file

output_file.write(' '.join(map(str,V)))

output_file.write(' ')

output_file.write(str(A))

output_file.write(' ')

output_file.write(' '.join(map(str,change)))

output_file.write(' ')

output_file.write(str(total_coins))

output_file.write(' ')

# convert the string to a array of characters

V = input_file.readline().split(' ')

# get the next line

A = input_file.readline()

# close the files

input_file.close()

output_file.close()