#define STRINGIFY2(x) # x #define STRINGIFY(x) STRINGIFY2(x) #define JOIN2(x,y) x ## y #define JOIN(x,y) JOIN2(x, y) #define X 22 JOIN(X, X) STRINGIFY(X) #define E 5 #define D E #define C D #define B C #define A B int x = E; main(void) { }