extern void memmove(void *dest, void *src, int bytes);
extern int memcmp(const char *a2, const char *a1, int bytes);
extern int strcmp(const char *a2, const char *a1);
extern int strncmp(const char *a2, const char *a1, int n);
extern int strlen(const char *c);
extern void memmove(void *dest, void *src, int bytes);
extern int memcmp(const char *a2, const char *a1, int bytes);
extern int strcmp(const char *a2, const char *a1);
extern int strncmp(const char *a2, const char *a1, int n);
extern int strlen(const char *c);