diff --git a/ShinHeeEul/202503/18 BOJ G1 Beads.md b/ShinHeeEul/202503/18 BOJ G1 Beads.md
new file mode 100644
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+++ b/ShinHeeEul/202503/18 BOJ G1 Beads.md	
@@ -0,0 +1,78 @@
+```java
+
+import java.io.*;
+import java.util.*;
+
+public class Main {
+
+	
+	static int[] segments;
+	static int size;
+    private static BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+    
+    private static int read() throws Exception {
+        return Integer.parseInt(br.readLine().trim());
+    }
+
+    public static void main(String[] args) throws Exception {
+        int T = read(); // 테스트 케이스 개수
+        
+        StringBuilder sb = new StringBuilder();
+        
+        for (int t = 0; t < T; t++) {
+            StringTokenizer st = new StringTokenizer(br.readLine());
+            int B = Integer.parseInt(st.nextToken());
+            int P = Integer.parseInt(st.nextToken());
+            int Q = Integer.parseInt(st.nextToken());
+
+            size = 1;
+            while (size < B) {
+                size <<= 1;
+            }
+
+            segments = new int[(size << 1) + 1];
+
+            for (int q = 0; q < P + Q; q++) {
+                st = new StringTokenizer(br.readLine());
+                char c = st.nextToken().charAt(0);
+                int a = Integer.parseInt(st.nextToken());
+                int b = Integer.parseInt(st.nextToken());
+
+                if (c == 'P') {
+                    update(a, b);
+                } else {
+                    sb.append(query(a, b, 2, 1, size)).append("\n");
+                }
+            }
+        }
+
+        System.out.print(sb); // 출력 최적화
+    }
+	
+	public static void update(int idx, int val) {
+		
+		idx += size;
+		
+		while(idx > 2) {
+			segments[idx] += val;
+			idx = (idx + 1) >> 1;
+		}
+		
+	}
+	
+	public static int query(int left, int right, int node, int start, int end) {
+		if(left > end || right < start) return 0;
+		
+		if(left <= start && end <= right) {
+			return segments[node];
+		}
+		
+		int mid = (start + end) >> 1;
+		
+		return query(left, right, (node << 1) - 1, start, mid) + query(left, right, node << 1, mid + 1, end);
+	}
+	
+
+}
+
+```