diff --git a/programmers/AddNumber.java b/programmers/AddNumber.java
new file mode 100644
index 0000000..a593780
--- /dev/null
+++ b/programmers/AddNumber.java
@@ -0,0 +1,19 @@
+import java.util.*;
+class Solution {
+    public static int solution(int[] numbers) {
+        boolean check[] = new boolean[10];
+
+
+        for(int i=0; i<numbers.length; i++)
+            check[numbers[i]] = true;
+
+        int answer = 0;
+
+        for(int i=1; i<check.length; i++){
+            if(check[i] == true) continue;
+            answer += i;
+        }
+
+        return answer;
+    }
+}