Easy solution

include

using namespace std;

int main() { string st; cin>>st;

string noSpace="";

for(int i=0;i<st.length();i++){
    if(st[i]!=' '){
        noSpace+=st[i];
    }
}

int size=noSpace.length();

//cout<<size<<endl;

int fl=floor(sqrt(size));
int cl=ceil(sqrt(size));

int mul=fl*cl;

// cout<

    while(mul<size){
        fl+=1;
        mul=fl*cl;
    }
}

vector<vector<char>>ans;

int x=0;


    for(int i=0;i<fl;i++){
        vector<char>temp;
        for(int j=0;j<cl;j++){
            if(x<size){
                temp.push_back(noSpace[x]);
                x+=1;
            }else{
                temp.push_back('-');
            }
        }
        ans.push_back(temp);
    }


string ans1="";
for(int i=0;i<ans[0].size();i++){
    for(int j=0;j<ans.size();j++){
        if(ans[j][i]!='-'){
            ans1+=ans[j][i];
        }
    }
    ans1+=" ";

}

cout<<ans1<<endl;





return 0;

}