diff --git a/verify/classic.py b/verify/classic.py
new file mode 100755
index 0000000..fbbe68f
--- /dev/null
+++ b/verify/classic.py
@@ -0,0 +1,221 @@
+#!/usr/bin/env python3
+
+import json
+from enum import Enum
+import functools
+from pprint import pprint
+from klotski import Group, Layout
+
+
+@functools.cache
+def global_data() -> dict[str, dict]:
+    return json.loads(open('./data/data.json').read())
+
+
+class Solution:
+    class Type(Enum):
+        X = 0
+        Y = 1
+        Z = 2
+
+    @staticmethod
+    def __solu_info(layout: str) -> tuple[int, int]:  # (max_step, ethnic_size)
+        cases = [x for x, y in global_data().items() if layout in y['solutions']]
+        steps = [global_data()[x]['step'] for x in cases]
+        assert min(steps) == 0
+        return max(steps), len(cases)
+
+    def __init__(self, code: str, solu_type: Type):
+        self.__code = code
+        self.__type = solu_type
+        self.__max_step, self.__ethnic_size = Solution.__solu_info(code)
+
+    @property
+    def code(self) -> str:
+        return self.__code
+
+    @property
+    def type(self) -> Type:
+        return self.__type
+
+    @property
+    def group(self) -> Group:
+        return self.layout.group
+
+    @property
+    def layout(self) -> Layout:
+        return Layout(self.code)
+
+    @property
+    def max_step(self) -> int:
+        return self.__max_step
+
+    @property
+    def ethnic_size(self) -> int:
+        return self.__ethnic_size
+
+    def __repr__(self):
+        val = f'{self.ethnic_size}, {self.max_step}'
+        return f'{self.code} {self.type.name} ({val})'
+
+
+class SoluGroup:
+    def __init__(self, name: str):
+        self.__name = name
+        self.__x_solus: list[Solution] = []
+        self.__y_solus: list[Solution] = []
+        self.__z_solus: list[Solution] = []
+
+    def add_solu(self, solu: Solution) -> None:
+        if solu.type == Solution.Type.X:
+            self.__x_solus.append(solu)
+        elif solu.type == Solution.Type.Y:
+            self.__y_solus.append(solu)
+        elif solu.type == Solution.Type.Z:
+            self.__z_solus.append(solu)
+
+    @property
+    def name(self) -> str:
+        return self.__name
+
+    @property
+    def solus(self) -> list[Solution]:
+        return self.__x_solus + self.__y_solus + self.__z_solus
+
+    @property
+    def solu_num(self) -> int:
+        return len(self.solus)
+
+    @property
+    def group(self) -> Group:
+        return self.solus[0].group
+
+    @property
+    def group_size(self) -> int:
+        return self.group.size
+
+    @property
+    def ethnic_sizes(self) -> list[int]:
+        return sorted([x.ethnic_size for x in self.solus], key=lambda x: -x)
+
+    @property
+    def max_ethnic_size(self) -> int:
+        return max(self.ethnic_sizes)
+
+    @property
+    def min_case(self) -> Layout:
+        return min(list(self.group.cases()))
+
+    @property
+    def min_solu(self) -> Layout:
+        return min(x.layout for x in self.solus)
+
+    def __repr__(self):
+        return (f'<SoluGroup {self.name} ({self.group_size}) '
+                f'[{self.min_solu}/{self.min_case}] {self.solu_num} -> {self.ethnic_sizes}>')
+
+
+class SoluPattern:
+    def __init__(self, *solu_groups: SoluGroup):
+        assert len(solu_groups) in [1, 2]
+        if len(solu_groups) == 1:
+            self.__is_single = True
+            self.__solu_m = solu_groups[0]
+        else:
+            self.__is_single = False
+            self.__solu_l, self.__solu_r = solu_groups  # TODO: confirm l/r
+            assert self.__solu_l.name[:-1] == self.__solu_r.name[:-1]
+            assert self.__solu_l.solu_num == self.__solu_r.solu_num
+            assert self.__solu_l.group_size == self.__solu_r.group_size
+            assert self.__solu_l.ethnic_sizes == self.__solu_r.ethnic_sizes
+
+    @property
+    def pattern_size(self) -> int:
+        if self.__is_single:
+            return self.__solu_m.group_size
+        return self.__solu_l.group_size * 2
+
+    @property
+    def ethnic_sizes(self) -> list[int]:
+        if self.__is_single:
+            return self.__solu_m.ethnic_sizes
+        return self.__solu_l.ethnic_sizes
+
+    @property
+    def max_ethnic_size(self) -> int:
+        return max(self.ethnic_sizes)
+
+    @property
+    def min_case(self) -> Layout:
+        if self.__is_single:
+            return self.__solu_m.min_case
+        else:
+            return min(self.__solu_l.min_case, self.__solu_r.min_case)
+
+    @property
+    def min_solu(self) -> Layout:
+        if self.__is_single:
+            return self.__solu_m.min_solu
+        else:
+            return min(self.__solu_l.min_solu, self.__solu_r.min_solu)
+
+    def __repr__(self):
+        if self.__is_single:
+            name = self.__solu_m.name
+            solu_num = f'{self.__solu_m.solu_num}'
+        else:
+            name = f'{self.__solu_l.name}|{self.__solu_r.name}'
+            solu_num = f'{self.__solu_l.solu_num}*2'
+        return (f'<SoluPattern {name} ({self.pattern_size}) '
+                f'[{self.min_solu}/{self.min_case}] {solu_num} -> {self.ethnic_sizes}>')
+
+
+def load_valid_solutions(num: int) -> list[Solution]:
+    raw = json.loads(open('./data/valid_solutions.json').read())
+    data_x = [Solution(x, Solution.Type.X) for x in raw[f'{num}x']]
+    data_y = [Solution(x, Solution.Type.Y) for x in raw[f'{num}y']]
+    data_z = [Solution(x, Solution.Type.Z) for x in raw[f'{num}z']]
+    return data_x + data_y + data_z
+
+
+def split_into_groups(solus: list[Solution]) -> list[SoluPattern]:
+    groups = {}
+    for solu in solus:
+        group = str(solu.group)
+        assert group[-1] in ['x', 'n', 'u', 'c', 'd']
+        if group not in groups:
+            groups[group] = SoluGroup(group)
+        groups[group].add_solu(solu)
+
+    pattern_tuples = []
+    for group in list(groups):
+        if group[-1] in ['x', 'n', 'u']:
+            pattern_tuples.append((group, ))
+        elif group[-1] == 'c':
+            pattern_tuples.append((group, f'{group[:-1]}d'))
+        elif group[-1] == 'd':
+            pattern_tuples.append((f'{group[:-1]}c', group))
+
+    patterns = []
+    for pattern_tuple in sorted(set(pattern_tuples)):
+        patterns.append(SoluPattern(*[groups[x] for x in pattern_tuple]))
+
+    return sorted(patterns, key=lambda x: (-x.pattern_size, -x.max_ethnic_size, x.min_solu))
+
+
+def main() -> None:
+
+    # solu = Solution('DAAF4CC', Solution.Type.X)
+    # print(solu)
+
+    # for solu_group in split_into_groups(load_valid_solutions(1)):
+    #     print(solu_group)
+
+    for num in range(6):  # 0/1/2/3/4/5
+        for solu_group in split_into_groups(load_valid_solutions(num)):
+            print(solu_group)
+        print('-' * 238)
+
+
+if __name__ == "__main__":
+    main()