C preprocessor evilness

eval.h

#if EVAL_INPUT % 10 == 0
  #define EVAL_D1 0
#elif EVAL_INPUT % 10 == 1
  #define EVAL_D1 1
#elif EVAL_INPUT % 10 == 2
  #define EVAL_D1 2
#elif EVAL_INPUT % 10 == 3
  #define EVAL_D1 3
#elif EVAL_INPUT % 10 == 4
  #define EVAL_D1 4
#elif EVAL_INPUT % 10 == 5
  #define EVAL_D1 5
#elif EVAL_INPUT % 10 == 6
  #define EVAL_D1 6
#elif EVAL_INPUT % 10 == 7
  #define EVAL_D1 7
#elif EVAL_INPUT % 10 == 8
  #define EVAL_D1 8
#elif EVAL_INPUT % 10 == 9
  #define EVAL_D1 9
#endif

#if (EVAL_INPUT/10) % 10 == 0
  #define EVAL_D2 0
#elif (EVAL_INPUT/10) % 10 == 1
  #define EVAL_D2 1
#elif (EVAL_INPUT/10) % 10 == 2
  #define EVAL_D2 2
#elif (EVAL_INPUT/10) % 10 == 3
  #define EVAL_D2 3
#elif (EVAL_INPUT/10) % 10 == 4
  #define EVAL_D2 4
#elif (EVAL_INPUT/10) % 10 == 5
  #define EVAL_D2 5
#elif (EVAL_INPUT/10) % 10 == 6
  #define EVAL_D2 6
#elif (EVAL_INPUT/10) % 10 == 7
  #define EVAL_D2 7
#elif (EVAL_INPUT/10) % 10 == 8
  #define EVAL_D2 8
#elif (EVAL_INPUT/10) % 10 == 9
  #define EVAL_D2 9
#endif

#define CAT_(x,y) x ## y
#define CAT(x,y) CAT_(x,y)

#define EVAL_RESULT CAT(EVAL_D2, EVAL_D1)

test.c

#define EVAL_INPUT 100/4

#include "eval.h"

int result = EVAL_RESULT;