diff --git a/crossword_generator.py b/crossword_generator.py
index fd71f85..e14d368 100644
--- a/crossword_generator.py
+++ b/crossword_generator.py
@@ -35,6 +35,7 @@ WORDS = [
 
 HORIZONTAL = "H"
 VERTICAL = "V"
+DIFFXY = 7
 
 
 @dataclass(frozen=True)
@@ -78,9 +79,28 @@ class CrosswordState:
         x_min, y_min, x_max, y_max = self.bounds()
         return (x_max - x_min + 1) * (y_max - y_min + 1)
 
-    def score(self) -> Tuple[int, int, int]:
-        # Maximize placed words first, then intersections, then prefer compact grids.
-        return (self.placed_words, self.intersections, -self.area())
+    def width(self) -> int:
+        x_min, _, x_max, _ = self.bounds()
+        return x_max - x_min + 1
+
+    def height(self) -> int:
+        _, y_min, _, y_max = self.bounds()
+        return y_max - y_min + 1
+
+    def shape_difference(self) -> int:
+        return abs(self.width() - self.height())
+
+    def score(self, diffxy: int) -> Tuple[int, int, int, int, int]:
+        # Prefer valid shapes first; within those, maximize placed words and intersections,
+        # then prefer squarer and more compact grids.
+        is_shape_valid = 1 if self.shape_difference() <= diffxy else 0
+        return (
+            is_shape_valid,
+            self.placed_words,
+            self.intersections,
+            -self.shape_difference(),
+            -self.area(),
+        )
 
 
 class CrosswordGenerator:
@@ -90,6 +110,7 @@ class CrosswordGenerator:
         *,
         max_candidates_per_word: int = 12,
         time_limit_seconds: float = 8.0,
+        diffxy: int = DIFFXY,
     ) -> None:
         normalized = [self._normalize(word) for word in words]
         unique_words = list(dict.fromkeys(word for word in normalized if len(word) >= 2))
@@ -97,6 +118,7 @@ class CrosswordGenerator:
         self.best_state = CrosswordState(grid={}, placements=[], intersections=0)
         self.max_candidates_per_word = max_candidates_per_word
         self.time_limit_seconds = time_limit_seconds
+        self.diffxy = diffxy
         self.started_at = 0.0
         self.visited: Dict[Tuple[frozenset, Tuple[str, ...]], Tuple[int, int, int]] = {}
         self.nodes_visited = 0
@@ -151,7 +173,7 @@ class CrosswordGenerator:
         if time.perf_counter() - self.started_at > self.time_limit_seconds:
             return
 
-        if state.score() > self.best_state.score():
+        if state.score(self.diffxy) > self.best_state.score(self.diffxy):
             self.best_state = state.copy()
 
         if not remaining_words:
@@ -167,9 +189,10 @@ class CrosswordGenerator:
 
         signature = (frozenset(state.grid.items()), tuple(sorted(remaining_words)))
         best_seen = self.visited.get(signature)
-        if best_seen is not None and best_seen >= state.score():
+        current_score = state.score(self.diffxy)
+        if best_seen is not None and best_seen >= current_score:
             return
-        self.visited[signature] = state.score()
+        self.visited[signature] = current_score
 
         next_word = self._select_next_word(state, remaining_words)
         candidates = self._generate_candidates(state, next_word)
@@ -206,8 +229,8 @@ class CrosswordGenerator:
         message = (
             f"\r{frame} elaborazione... "
             f"nodi={self.nodes_visited} "
-            f"migliore={self.best_state.placed_words} parole, {self.best_state.intersections} incroci "
-            f"attuale={state.placed_words} parole "
+            f"migliore={self.best_state.placed_words} parole, {self.best_state.intersections} incroci, diff={self.best_state.shape_difference()} "
+            f"attuale={state.placed_words} parole, diff={state.shape_difference()} "
             f"t={elapsed:0.1f}s"
         )
         print(message, end="", file=sys.stderr, flush=True)
@@ -371,6 +394,8 @@ def main() -> None:
     print("Miglior soluzione trovata")
     print(f"Parole inserite: {solution.placed_words}/{len(generator.words)}")
     print(f"Intersezioni totali: {solution.intersections}")
+    print(f"Dimensioni: {solution.width()} colonne x {solution.height()} righe")
+    print(f"Differenza righe/colonne: {solution.shape_difference()} (vincolo DIFFXY={generator.diffxy})")
     print(f"Area occupata: {solution.area()}")
     print()
     print(render_grid(solution.grid, solution.placements))