diff --git a/README.md b/README.md
index c604e3b..cb5034a 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,2 @@
 # go-study
-
+git add test
\ No newline at end of file
diff --git a/helloworld b/helloworld
new file mode 100755
index 0000000..f0a32b6
Binary files /dev/null and b/helloworld differ
diff --git a/helloworld.go b/helloworld.go
new file mode 100644
index 0000000..87595e3
--- /dev/null
+++ b/helloworld.go
@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+    fmt.Println("hello world")
+}
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..1734462
--- /dev/null
+++ b/main.go
@@ -0,0 +1,35 @@
+package main
+
+import (
+	"fmt"
+	"net"
+	"sync"
+	"time"
+)
+
+func scanPort(host string, port int, wg *sync.WaitGroup) {
+	defer wg.Done()
+
+	address := fmt.Sprintf("%s:%d", host, port)
+	conn, err := net.DialTimeout("tcp", address, 500*time.Millisecond)
+	if err == nil {
+		fmt.Printf("[OPEN] %s\n", address)
+		conn.Close()
+	}
+}
+
+func main() {
+	var wg sync.WaitGroup
+
+	host := "134.185.113.169" // 스캔할 IP 주소
+	startPort := 1
+	endPort := 1024
+
+	for port := startPort; port <= endPort; port++ {
+		wg.Add(1)
+		go scanPort(host, port, &wg)
+	}
+
+	wg.Wait()
+	fmt.Println("✅ 스캔 완료.")
+}