void key_input (BFiles bfs, int nkeys, int cache);
ISAMC_M key_isamc_m (Res res);
int merge_sort (char **buf, int from, int to);
void key_input (BFiles bfs, int nkeys, int cache);
ISAMC_M key_isamc_m (Res res);
int merge_sort (char **buf, int from, int to);