Declared identifier reported as undeclared

I'm doing an exercise out of a book I've been using (Deitel: C How to Program) and I'm trying to make a program that determines perfect numbers.

Everything was going well but all the sudden it is saying alot of my variables aren't declare and there is a problem with my function!

Code:

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exercise3.c:44: error: syntax error before "int"
exercise3.c:45: error: redeclaration of `check'
exercise3.c:44: error: `check' previously declared here
exercise3.c:62: error: `counter' undeclared (first use in this function)
exercise3.c:62: error: (Each undeclared identifier is reported only once
exercise3.c:62: error: for each function it appears in.)

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Code:

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#include <stdio.h>

int perfect(int number);

int main()
  {
  int input = 0, factor1, factor2, counter = 2, check = 0;

  scanf("%d", &input);

  counter = 2;

  if ( perfect(input) == 1)
      {
      printf("%d is a perfect number\n", input);
     
      for(factor1 = 2; factor1 <= (input - 1); ++factor1)
        {
        for (factor2 = 2; factor2 <= (input - 1); ++factor2)
            {
            if ( (factor1 * factor2) == input)
              {
                  if (factor1 != check && factor2 != check)
                  {

                    if ( (counter % 2) == 0)               
                        check = factor2;
                    ++counter;
                  printf("%d + %d + ", factor1, factor2);
                  }
              }
            }
        }
      printf("1 = %d\n", input);
      }

 

  return 0;
  }

int perfect (int number)
{
int factor1, factor2, check = 0, perfect = 0, int counter = 2;
int check = 2;

for (factor1 = 2; factor1 <= (number - 1); ++factor1)
  {
  for (factor2 = 2; factor2 <= (number - 1); ++factor2)
      {

      if ( (factor1 * factor2) == number)
        {
/* -------------------------------------------------------------------------------------- */
/* the check needs to be worked out to register at the half way point through            */
/* factoring so numbers aren't counted twice                                              */
/* -------------------------------------------------------------------------------------- */ 
      if (factor1 != check && factor2 != check)
            {
            perfect = perfect + factor1 + factor2;

            if ( (counter % 2) == 0 )
              check = factor2;
            ++counter;

            printf(" factor1 is %d\n factor2 is %d\n check is %d\n",
factor1, factor2, check);
            printf(" perfect is %d\n", perfect);

            }
        }

      }
  }

  if ( (perfect + 1) == number)
      return 1;
  else
      return 0;
}

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Does anyone know what the deal is?

Code:

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int factor1, factor2, check = 0, perfect = 0, int counter = 2;
int check = 2;

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Notice the syntax error before int check = 2;

Read that line above int check = 2; carefully.

Code:

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int factor1, factor2, check = 0, perfect = 0, int counter = 2;
int check = 2;

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That int before counter shouldn't be there if you're using commas between declarations. You're redeclaring check on the next line.

Code:

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int factor1, factor2, check = 2, perfect = 0, counter = 2;

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