class Solution {
public:
    string reformatNumber(string number) {
        string di;
        for(auto ch : number)
        {
            if(isdigit(ch))
            di.push_back(ch);
        }

        int size = di.size();
        int pos = 0;
        string ans;
        while(size)
        {
            if(size>4)
            {
                ans += di.substr(pos,3)+"-";
                pos += 3;
                size -= 3;
            }
            else if(size == 4)
            {
                ans += di.substr(pos,2) + "-"+di.substr(pos+2,2);
                break;
               
            }
            else{
                 ans += di.substr(pos,size);
                 break;
            }
        }
        return ans;
    }
};