diff --git a/packages/hydrooj/src/script/rating.ts b/packages/hydrooj/src/script/rating.ts
index fbb33bc99..6b122d162 100644
--- a/packages/hydrooj/src/script/rating.ts
+++ b/packages/hydrooj/src/script/rating.ts
@@ -84,13 +84,14 @@ async function runContest(...arg: any[]) {
 }
 
 export async function calcLevel(domainId: string, report: Function) {
-    const ducnt = await domain.getMultiUserInDomain(domainId).count();
+    const filter = { rp: { $ne: 1500, $exists: true } };
+    const ducnt = await domain.getMultiUserInDomain(domainId, filter).count();
     if (!ducnt) return;
     let last = { rp: null };
     let rank = 0;
     let count = 0;
     const coll = global.Hydro.service.db.collection('domain.user');
-    const ducur = domain.getMultiUserInDomain(domainId).project({ rp: 1 }).sort({ rp: -1 });
+    const ducur = domain.getMultiUserInDomain(domainId, filter).project({ rp: 1 }).sort({ rp: -1 });
     let bulk = coll.initializeUnorderedBulkOp();
     while (await ducur.hasNext()) {
         const dudoc = await ducur.next();
diff --git a/packages/hydrooj/src/utils.ts b/packages/hydrooj/src/utils.ts
index 81f587467..64ce8729e 100644
--- a/packages/hydrooj/src/utils.ts
+++ b/packages/hydrooj/src/utils.ts
@@ -32,4 +32,14 @@ export function logAndReturn(logger: Logger) {
     };
 }
 
+const RE_USER = /(?:^|\s)(@)([^ ]{3,255}?)(?=\s|$)/g;
+
+export function getRelatedUsers(content: string) {
+    const results = [];
+    let res: string[];
+    // eslint-disable-next-line no-cond-assign
+    while (res = RE_USER.exec(content)) results.push(res[2]);
+    return results;
+}
+
 export * from '@hydrooj/utils/lib/utils';