competitors for the grand prize of a toaster! To win, he must eat more slices of bread than all the other competitors at the tournament. Being a contrarian individual, wishes to lose against each competitor. has confidence in his abilities, but he also has a strange compulsion to eat a **prime** number of bread slices in each round.

Wanting to know his chances of losing, , the number of slices that his competitors can eat per round. As is very hungry, help him determine the maximum number of slices he can eat in each round while still losing to his competitors.

has determined**Note:** For 50% of points, and

#### Input Specification

On the first line, one integer representing the number of competitors. On the second line, space separated integers , representing the amount of bread that the competitor can eat.

#### Output Specification

Output lines, with the line representing the largest number of bread slices can eat while still losing against the competitor. If there is no way that can lose the round, output `no can do`

.

#### Sample Input

```
3
5 7 1
```

#### Sample Output

```
3
5
no can do
```

#### Explanation of Sample Input

In the first two rounds,

can eat 3 and 5 slices respectively. In the third round, there is no valid number of slices that can eat and still lose.
## Comments