for (int i = 1; i <= k - 1 + (curr == start); i++) {
		if ((int)mpp[len].size()) {

            int last = mpp[len].back();
            mpp[len].pop_back();
			ans.pb({ curr, last });
			len++;
			dfs(last);
			len--;
			//mpp[len].pop_back();

		}else break;// <<<<-------------SEE
	}