diff --git a/judge/contest_format/__init__.py b/judge/contest_format/__init__.py
index 8d2ccc9..9f6d628 100644
--- a/judge/contest_format/__init__.py
+++ b/judge/contest_format/__init__.py
@@ -4,4 +4,5 @@ from judge.contest_format.ecoo import ECOOContestFormat
 from judge.contest_format.icpc import ICPCContestFormat
 from judge.contest_format.ioi import IOIContestFormat
 from judge.contest_format.new_ioi import NewIOIContestFormat
+from judge.contest_format.ultimate import UltimateContestFormat
 from judge.contest_format.registry import choices, formats
diff --git a/judge/contest_format/ultimate.py b/judge/contest_format/ultimate.py
new file mode 100644
index 0000000..7960d02
--- /dev/null
+++ b/judge/contest_format/ultimate.py
@@ -0,0 +1,55 @@
+from django.utils.translation import gettext_lazy
+
+from judge.contest_format.ioi import IOIContestFormat
+from judge.contest_format.registry import register_contest_format
+from django.db.models import Min, OuterRef, Subquery
+
+# This contest format only counts last submission for each problem.
+
+
+@register_contest_format("ultimate")
+class UltimateContestFormat(IOIContestFormat):
+    name = gettext_lazy("Ultimate")
+
+    def update_participation(self, participation):
+        cumtime = 0
+        score = 0
+        format_data = {}
+
+        queryset = participation.submissions
+        if self.contest.freeze_after:
+            queryset = queryset.filter(
+                submission__date__lt=participation.start + self.contest.freeze_after
+            )
+
+        queryset = (
+            queryset.values("problem_id")
+            .filter(
+                id=Subquery(
+                    queryset.filter(problem_id=OuterRef("problem_id"))
+                    .order_by("-id")
+                    .values("id")[:1]
+                )
+            )
+            .values_list("problem_id", "submission__date", "points")
+        )
+
+        for problem_id, time, points in queryset:
+            if self.config["cumtime"]:
+                dt = (time - participation.start).total_seconds()
+                if points:
+                    cumtime += dt
+            else:
+                dt = 0
+            format_data[str(problem_id)] = {
+                "time": dt,
+                "points": points,
+            }
+            score += points
+
+        self.handle_frozen_state(participation, format_data)
+        participation.cumtime = max(cumtime, 0)
+        participation.score = round(score, self.contest.points_precision)
+        participation.tiebreaker = 0
+        participation.format_data = format_data
+        participation.save()
diff --git a/judge/migrations/0167_ultimate_contest_format.py b/judge/migrations/0167_ultimate_contest_format.py
new file mode 100644
index 0000000..636e882
--- /dev/null
+++ b/judge/migrations/0167_ultimate_contest_format.py
@@ -0,0 +1,32 @@
+# Generated by Django 3.2.18 on 2023-09-01 00:09
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("judge", "0166_display_rank_index"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="contest",
+            name="format_name",
+            field=models.CharField(
+                choices=[
+                    ("atcoder", "AtCoder"),
+                    ("default", "Default"),
+                    ("ecoo", "ECOO"),
+                    ("icpc", "ICPC"),
+                    ("ioi", "IOI"),
+                    ("ioi16", "New IOI"),
+                    ("ultimate", "Ultimate"),
+                ],
+                default="default",
+                help_text="The contest format module to use.",
+                max_length=32,
+                verbose_name="contest format",
+            ),
+        ),
+    ]