diff --git a/utils/data.py b/utils/data.py
index d749ae36087e87f84b4ec4017d76613b8618728b..37e70374de34c2165d97e61513751708275bab4e 100644
--- a/utils/data.py
+++ b/utils/data.py
@@ -116,8 +116,9 @@ class Problem(object):
                 block_text += '\n'
             
             # board_xy = math.ceil(2 * math.sqrt(num_tiles))
-            board_xy = math.ceil(3 * math.sqrt(num_tiles))
-            problem_text += f'SIZE {board_xy}X{board_xy}\n'
+            group_x = min(math.ceil(3 * math.sqrt(num_tiles)), self.size[0])
+            group_y = min(math.ceil(3 * math.sqrt(num_tiles)), self.size[1])
+            problem_text += f'SIZE {group_x}X{group_y}\n'
             problem_text += f'BLOCK_NUM {len(g)}\n'
             problem_text += '\n'
             problem_text += block_text