class Solution {
public:
    vector<vector<int>> insert(vector<vector<int>>& a, vector<int>& b) {
        vector<vector<int>> res;
        int k=0;
        while(k<a.size()&&a[k][1]<b[0])res.push_back(a[k++]);
        if(k<a.size())
        {
            b[0]=min(b[0], a[k][0]);
            while(k<a.size()&&a[k][0]<=b[1])b[1]=max(b[1], a[k++][1]);
        }
        res.push_back(b);
        while(k<a.size())res.push_back(a[k++]);
        return res;
    }
};