we can see that exclude 2 and 3,other numbers just compute how many "3" (n-2) have,the reason we need to -2 is that 4(2×2) is greater than 3(1×2).

```
public class Solution {
public int integerBreak(int n) {
if (n==2) return 1;
if (n==3) return 2;
int num_of_3 = (n-2)/3;
int pow_of_3 = (int) Math.pow(3,num_of_3);
return pow_of_3*(n-3*num_of_3);
}
}
```