#define str(s) # s#define xstr(s) str(s)#define debug(s, t) printf("x" # s "= %d, x" # t "= %s", \	x ## s, x ## t)#define INCFILE(n) vers ## n#define glue(a, b) a ## b#define xglue(a, b) glue(a, b)#define HIGHLOW "hello"#define LOW LOW ", world"debug(1, 2);fputs(str(strncmp("abc\0d", "abc", '\4') // this goes away	== 0) str(: @\n), s);\#include xstr(INCFILE(2).h)glue(HIGH, LOW);xglue(HIGH, LOW)