Setting value back?

[blurx]

Say I have the following code below, and I want to print out the original value of a, how would I do that?

  printf("Enter a positive number: ");
  scanf("%d", &a);

  if(a > 0){
    while(a > 0){
      digits = a % 10;
      a = a / 10;
      if(digits == 0) printf(" ");
      p++;
    }
  }