diff --git a/8.3/input_data b/8.3/input_data
deleted file mode 100644
index 25f412a3e1fbddcd4014c99026247350089b6b7b..0000000000000000000000000000000000000000
--- a/8.3/input_data
+++ /dev/null
@@ -1 +0,0 @@
--200
diff --git a/8.3/output_data b/8.3/output_data
deleted file mode 100644
index 3bb9c68d22a6d55398bad302c5f096a20224616b..0000000000000000000000000000000000000000
--- a/8.3/output_data
+++ /dev/null
@@ -1,2 +0,0 @@
-Hello, World -200      
-Error: It is negative
diff --git a/README.md b/README.md
deleted file mode 100644
index 9364e1eb0e0e9ab26deeecb120a65b372d0cfa8c..0000000000000000000000000000000000000000
--- a/README.md
+++ /dev/null
@@ -1,11 +0,0 @@
-# battle_c
-
-## Jangwon Lee - Team 1
-
-실전코딩2 실습
-
-## printf
-
-### stdio.h
-
-* stderr, stdout, stdin에 대해서 배움
\ No newline at end of file
diff --git a/three_files/func.c b/three_files/func.c
deleted file mode 100644
index 8f2a8a6e40a91256acba971276d98aaa8b544392..0000000000000000000000000000000000000000
--- a/three_files/func.c
+++ /dev/null
@@ -1,11 +0,0 @@
-#include "func.h"
-
-int func1(int a)
-{
-	return (a * 10);
-}
-
-int func2(int a)
-{
-	return (a * 2);
-}
\ No newline at end of file
diff --git a/three_files/func.h b/three_files/func.h
deleted file mode 100644
index 0aa7479313d3ebc2e5afe4a49b3b8621d31e8516..0000000000000000000000000000000000000000
--- a/three_files/func.h
+++ /dev/null
@@ -1,3 +0,0 @@
-#pragma once
-#define DF(a) ((a)*(a))
-extern int func1(int x);
\ No newline at end of file
diff --git a/three_files/main.c b/three_files/main.c
deleted file mode 100644
index 2f2c8826140c1448b4307dd70d64a9d84840555c..0000000000000000000000000000000000000000
--- a/three_files/main.c
+++ /dev/null
@@ -1,18 +0,0 @@
-#include <stdio.h>
-#include "func.h"
-
-int func_name_or_id()
-{
-#ifdef PRINT_ID
-	printf("201920756");
-	return 0;
-#else
-	printf("�����");
-	return 1;
-#endif
-}
-
-int main()
-{
-	func_name_or_id();
-}