产出的代码是:

```python
def dfs(pos, last, vis):
if pos == 12: # base case: all numbers have been used
return 1
res = 0
for i in range(1, 12):
if not vis[i] and abs(i - last) > 1:
vis[i] = True
res += dfs(pos + 1, i, vis)
vis[i] = False # backtrack
return res

# Initialize
vis = [False] * 12
# Start DFS
total = dfs(1, 0, vis)
total
```