class Solution {
public:
    int findNumberAppearingOnce(vector<int>& nums) {
        int move = 1;
        int res = 0;
        for(int i = 0; i < 32; i++, move ++){
            int cnt = 0;
            for(int num : nums)
                if((num >> move) & 1)   cnt ++;
            if(cnt % 3)     res |= (1 << move);
        }
        return res;
    }
};