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I'm trying to solve this problem:

Enter two numbers from keyboard with at least three digits.

Print the number that have the digits sum greater.

Inside of a function I have tried to print the values of variables. The values of those variables is not printed, so I think that the function is not being executed.

a = input('\n Enter the first number : ' )
x = sum([a])
print('\n The sum of the digits number ' +str(x)+ ' este : %d' %x)
b = input('\n Enter the second number : ')
y = sum([b])
print('\n The sum of the digits number ' +str(y)+ ' este : %d' %y)
def sum(param):
 var = 0
 while(param != 0):
 var += (param % 10)
 print(var)
 param /= 10
 print(param)
 return var