#include #include const char *serial = "\x31\x3e\x3d\x26\x31"; int check(char *ptr) { int i; int hash = 0xABCD; for (i = 0; ptr[i]; i++) hash += ptr[i] ^ serial[i % 5]; return hash; } int main(int ac, char **av) { int ret; if (ac != 2) return -1; ret = check(av[1]); if (ret == 0xad6d) printf("Win\n"); else printf("fail\n"); return 0; }