diff --git a/README.md b/README.md
index 02271b2..5ad4b37 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,4 @@
 # mastering-github
 git&github 실습을 위한 저장소
+
+this is *edit test* for 실습
diff --git a/main.c b/main.c
new file mode 100644
index 0000000..d982f76
--- /dev/null
+++ b/main.c
@@ -0,0 +1,6 @@
+#include <stdio.h>
+
+int main() {
+	printf("hello world\n");
+	return 0;
+}