class Solution {
public:
    int maxProductAfterCutting(int length) {
        if(length <= 3) return length - 1;
        int res = 1;
        if(length % 3 == 1) res *= 4, length -= 4;
        if(length % 3 == 2) res *= 2, length -= 2;
        while(length)   res *= 3, length -= 3;
        return res;
    }
};