From 723f0bd71a5c9d1370f26821662b7e5ac3ebea2e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=EA=B0=95=EC=8B=A0=EC=A7=80?=
 <101992179+ksinji@users.noreply.github.com>
Date: Sat, 24 Jan 2026 00:55:49 +0900
Subject: [PATCH] =?UTF-8?q?[20260124]=20BOJ=20/=20G4=20/=20=EA=B1=B0?=
 =?UTF-8?q?=EC=A7=93=EB=A7=90=20/=20=EA=B0=95=EC=8B=A0=EC=A7=80?=
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---
 ...J \352\261\260\354\247\223\353\247\220.md" | 83 +++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 "ksinji/202601/24 BOJ \352\261\260\354\247\223\353\247\220.md"

diff --git "a/ksinji/202601/24 BOJ \352\261\260\354\247\223\353\247\220.md" "b/ksinji/202601/24 BOJ \352\261\260\354\247\223\353\247\220.md"
new file mode 100644
index 00000000..4922383b
--- /dev/null
+++ "b/ksinji/202601/24 BOJ \352\261\260\354\247\223\353\247\220.md"	
@@ -0,0 +1,83 @@
+```java
+import java.io.*;
+import java.util.*;
+
+public class Main {
+    static int n, m;
+    static int[] parent;
+
+    public static void main(String[] args) throws Exception {
+        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
+        StringTokenizer st = new StringTokenizer(br.readLine());
+
+        n = Integer.parseInt(st.nextToken());
+        m = Integer.parseInt(st.nextToken());
+
+        parent = new int[n + 1];
+        for (int i = 1; i <= n; i++) parent[i] = i;
+
+        st = new StringTokenizer(br.readLine());
+        int truthCnt = Integer.parseInt(st.nextToken());
+        int[] truth = new int[truthCnt];
+        for (int i = 0; i < truthCnt; i++) {
+            truth[i] = Integer.parseInt(st.nextToken());
+        }
+
+        if (truthCnt == 0) {
+            for (int i = 0; i < m; i++) {
+                br.readLine();
+            }
+            System.out.println(m);
+            return;
+        }
+
+        for (int i = 1; i < truthCnt; i++) {
+            union(truth[0], truth[i]);
+        }
+
+        int[][] party = new int[m][];
+        for (int i = 0; i < m; i++) {
+            st = new StringTokenizer(br.readLine());
+            int k = Integer.parseInt(st.nextToken());
+            int[] member = new int[k];
+            for (int j = 0; j < k; j++) {
+                member[j] = Integer.parseInt(st.nextToken());
+            }
+            party[i] = member;
+
+            for (int j = 1; j < k; j++) {
+                union(member[0], member[j]);
+            }
+        }
+
+        int truthGroup = find(truth[0]);
+        int ans = 0;
+
+        for (int i = 0; i < m; i++) {
+            boolean ok = true;
+            for (int person : party[i]) {
+                if (find(person) == truthGroup) {
+                    ok = false;
+                    break;
+                }
+            }
+            if (ok) ans++;
+        }
+
+        System.out.println(ans);
+    }
+
+    static int find(int x) {
+        if (parent[x] == x) return x;
+        return parent[x] = find(parent[x]);
+    }
+
+    static void union(int a, int b) {
+        a = find(a);
+        b = find(b);
+        if (a == b) return;
+        parent[b] = a;
+    }
+}
+
+```