diff --git a/a3/binary_search_tree.c b/a3/binary_search_tree.c
index 2959014..6f85c24 100644
--- a/a3/binary_search_tree.c
+++ b/a3/binary_search_tree.c
@@ -2,7 +2,11 @@
 #include <stdlib.h>
 #include <string.h>
 #include "binary_search_tree.h"
-
+node_t *build_tree(int *, size_t );
+void add_dereva(node_t* , int );
+void free_tree(node_t *);
+int *sorted_data(node_t *);
+int count_size(node_t *);
 
 node_t *build_tree(int *tree_data, size_t tree_data_len){
     node_t* first=malloc(sizeof(node_t));
@@ -10,7 +14,7 @@ node_t *build_tree(int *tree_data, size_t tree_data_len){
     first->right=NULL;
     first->left=NULL;
 
-    for(int i=1; i<tree_data_len; i++){
+    for(unsigned int i=1; i<tree_data_len; i++){
          add_dereva( first, tree_data[i]);
     }
 }