diff --git a/main.py b/main.py
index 78ef184..0730604 100644
--- a/main.py
+++ b/main.py
@@ -1,4 +1,5 @@
 import itertools
+from copy import deepcopy
 from itertools import combinations, combinations_with_replacement
 
 OP_PLUS = "PLUS"
@@ -24,7 +25,7 @@ OP_LAMBDAS = {
 }
 
 BOX_H_LABELS = 'ABCDEF'
-BOX_V_LABELS = '123456'
+BOX_V_LABELS = '654321'
 
 
 class Block(object):
@@ -33,7 +34,7 @@ class Block(object):
         self.operation = operation
         self.result = result
 
-        self.solutions = []
+        self.solutions = set()
 
         self.verify()
 
@@ -86,20 +87,49 @@ class Block(object):
         self.generate_hypotheses(grid_size)
         for hyp in self.generate_hypotheses(grid_size):
             for perm in itertools.permutations(hyp):
-                sol = list(zip(self.boxes, perm))
-                self.solutions.append(sol)
+                sol = tuple(zip(self.boxes, perm))
+                self.solutions.add(sol)
 
     def __repr__(self):
         return 'Block {}'.format(self.boxes)
 
 
+def translate_box_to_rc(box):
+    return BOX_V_LABELS.index(box[1]), BOX_H_LABELS.index(box[0])
+
+
+def has_line_integrity(line):
+    existing_values = set()
+    for value in line:
+        if value in existing_values:
+            return False
+        if value != 0:
+            existing_values.add(value)
+    return True
+
+
+def fill_grid(grid, solution):
+    box_values = []
+    for box_value in solution:
+        box_values.append(box_value)
+    for box, value in box_values:
+        br, bc = translate_box_to_rc(box)
+        grid[br][bc] = value
+    return grid
+
+
 class Game(object):
     def __init__(self, grid_size, blocks):
         self.blocks = blocks
         self.grid_size = grid_size
-        self.grid = [[0] * grid_size] * grid_size
         self.verify()
 
+        for block in self.blocks:
+            block.generate_solutions(self.grid_size)
+
+    def init_grid(self):
+        return [[0] * self.grid_size for _ in range(self.grid_size)]
+
     def verify(self):
         found = set()
         for block in self.blocks:
@@ -116,34 +146,52 @@ class Game(object):
                     rv.add(block)
         return rv
 
-    def solve(self):
-        for block in self.blocks:
-            block.generate_solutions(self.grid_size)
-        # row_permutations = itertools.permutations(1, self.grid_size + 1)
-        for row_id, row in enumerate(self.grid):
-            for col_id, cell in enumerate(row):
-                self.grid[row_id][col_id] = self.generate_possible_cell_values(row_id, col_id)
+    def check_grid(self, grid):
+        for row in grid:
+            if not has_line_integrity(row):
+                return False
+        for col_id in range(self.grid_size):
+            col = [grid[r][col_id] for r in range(self.grid_size)]
+            if not has_line_integrity(col):
+                return False
+        return True
+
+    def solve(self, grid, current_block_id=0):
+        block = self.blocks[current_block_id]
+        for solution in block.solutions:
+            prev_grid = deepcopy(grid)
+            grid = fill_grid(grid, solution)
+            if not self.check_grid(grid):
+                grid = prev_grid
+            else:
+                if current_block_id == len(self.blocks) - 1:
+                    return grid
+                sol = self.solve(deepcopy(grid), current_block_id + 1)
+                if sol:
+                    return sol
 
 
 def main():
     game = Game(grid_size=6,
                 blocks=[
-                    Block(boxes=['A6', 'A5'], operation=OP_MINUS, result=2),
-                    Block(boxes=['B6', 'C6', 'C5'], operation=OP_MULTIPLY, result=20),
-                    Block(boxes=['D6', 'D5', 'E5'], operation=OP_PLUS, result=11),
-                    Block(boxes=['E6', 'F6', 'F5'], operation=OP_MULTIPLY, result=18),
-                    Block(boxes=['A4', 'B4', 'B5'], operation=OP_PLUS, result=9),
-                    Block(boxes=['C4', 'D4'], operation=OP_MINUS, result=5),
-                    Block(boxes=['E4', 'F4', 'E3', 'F3'], operation=OP_MULTIPLY, result=80),
-                    Block(boxes=['D3', 'C3'], operation=OP_MINUS, result=1),
-                    Block(boxes=['A3', 'B3', 'B2'], operation=OP_PLUS, result=12),
-                    Block(boxes=['C2', 'D2'], operation=OP_DIVIDE, result=2),
-                    Block(boxes=['A1', 'A2'], operation=OP_PLUS, result=5),
-                    Block(boxes=['B1'], operation=OP_NONE, result=6),
-                    Block(boxes=['C1', 'D1', 'E1'], operation=OP_MULTIPLY, result=60),
-                    Block(boxes=['F1', 'E2', 'F2'], operation=OP_MULTIPLY, result=9),
+                    Block(boxes=['A6', 'B6', 'C6', 'D6'], operation=OP_MULTIPLY, result=120),
+                    Block(boxes=['E6', 'E5', 'E4', 'F4'], operation=OP_PLUS, result=17),
+                    Block(boxes=['F6', 'F5'], operation=OP_PLUS, result=5),
+                    Block(boxes=['A5', 'B5'], operation=OP_MINUS, result=1),
+                    Block(boxes=['C5', 'C4'], operation=OP_DIVIDE, result=2),
+                    Block(boxes=['D5', 'D4'], operation=OP_PLUS, result=3),
+                    Block(boxes=['A4', 'A3'], operation=OP_PLUS, result=5),
+                    Block(boxes=['B4', 'B3', 'C3'], operation=OP_MULTIPLY, result=30),
+                    Block(boxes=['D3', 'D2', 'E2'], operation=OP_MULTIPLY, result=15),
+                    Block(boxes=['B2', 'C2', 'C1'], operation=OP_MULTIPLY, result=10),
+                    Block(boxes=['A2'], operation=OP_NONE, result=6),
+                    Block(boxes=['A1', 'B1'], operation=OP_DIVIDE, result=3),
+                    Block(boxes=['D1', 'E1'], operation=OP_MINUS, result=1),
+                    Block(boxes=['F1', 'F2', 'F3', 'E3'], operation=OP_PLUS, result=16),
                 ])
-    game.solve()
+    grid = game.solve(grid=game.init_grid())
+    for line in grid:
+        print(line)
 
 
 if __name__ == '__main__':