Question 14
A mouse starts from the top left-most unit square marked with “ $ I $”, follows a route to form the word “IMAS2019” by moving from one square to another square that share a common side. How many different routes of eight squares are there?
| I | M | A | S | |
| --- | --- | --- | --- | --- |
| M | A | S | 2 | 0 |
| A | S | 2 | 0 | 1 |
| S | 2 | 0 | 1 | 9 |
| | 0 | 1 | 9 | |
| I | M | A | S | |
| --- | --- | --- | --- | --- |
| M | A | S | 2 | 0 |
| A | S | 2 | 0 | 1 |
| S | 2 | 0 | 1 | 9 |
| | 0 | 1 | 9 | |