diff --git a/internal/api/contest_messages.go b/internal/api/contest_messages.go
index bae3378..ebaeace 100644
--- a/internal/api/contest_messages.go
+++ b/internal/api/contest_messages.go
@@ -77,7 +77,7 @@ func (f *CreateContestMessageForm) Update(
 ) error {
 	errors := errorFields{}
 	if f.ParentID == nil {
-		if len(f.Title) < 4 {
+		if len(f.Title) < 2 {
 			errors["title"] = errorField{
 				Message: localize(c, "Title is too short."),
 			}
@@ -89,7 +89,7 @@ func (f *CreateContestMessageForm) Update(
 	} else {
 		f.Title = ""
 	}
-	if len(f.Description) < 4 {
+	if len(f.Description) < 2 {
 		errors["description"] = errorField{
 			Message: localize(c, "Description is too short."),
 		}
@@ -167,7 +167,7 @@ func (f SubmitContestQuestionForm) Update(
 	c echo.Context, o *models.ContestMessage,
 ) error {
 	errors := errorFields{}
-	if len(f.Title) < 4 {
+	if len(f.Title) < 2 {
 		errors["title"] = errorField{
 			Message: localize(c, "Title is too short."),
 		}
diff --git a/internal/api/contests.go b/internal/api/contests.go
index cc408cb..ed0d449 100644
--- a/internal/api/contests.go
+++ b/internal/api/contests.go
@@ -1032,10 +1032,11 @@ type ContestSolutions struct {
 }
 
 type contestSolutionsFilter struct {
-	ProblemID int64          `query:"problem_id"`
-	Verdict   models.Verdict `query:"verdict"`
-	BeginID   int64          `query:"begin_id"`
-	Limit     int            `query:"limit"`
+	ProblemID     int64          `query:"problem_id"`
+	ParticipantID int64          `query:"participant_id"`
+	Verdict       models.Verdict `query:"verdict"`
+	BeginID       int64          `query:"begin_id"`
+	Limit         int            `query:"limit"`
 }
 
 func (f *contestSolutionsFilter) Parse(c echo.Context) error {
@@ -1059,6 +1060,9 @@ func (f *contestSolutionsFilter) Filter(solution models.ContestSolution) bool {
 	if f.ProblemID != 0 && solution.ProblemID != f.ProblemID {
 		return false
 	}
+	if f.ParticipantID != 0 && solution.ParticipantID != f.ParticipantID {
+		return false
+	}
 	if f.BeginID != 0 && solution.ID > f.BeginID {
 		return false
 	}
@@ -1071,7 +1075,7 @@ func (v *View) observeContestSolutions(c echo.Context) error {
 	if !ok {
 		return fmt.Errorf("contest not extracted")
 	}
-	filter := contestSolutionsFilter{Limit: 250}
+	filter := contestSolutionsFilter{Limit: 50}
 	if err := filter.Parse(c); err != nil {
 		c.Logger().Warn(err)
 		return err