180. Consecutive Numbers

Write a SQL query to find all numbers that appear at least three times consecutively.

+----+-----+

| Id | Num |

+----+-----+

| 1  |  1  |

| 2  |  1  |

| 3  |  1  |

| 4  |  2  |

| 5  |  1  |

| 6  |  2  |

| 7  |  2  |

+----+-----+

For example, given the aboveLogstable,1is the only number that appears consecutively for at least three times.

# Write your MySQL query statement below

```

select l1.num from Logs l1, Logs l2, Logs l3 where l1.id-l2.id=1 and l1.num=l2.num and l2.id-l3.id=1 and l2.num=l3.num group by l1.num;

```