> #include <iostream>
> #include <cstdio>
> #include <vector>
> #include <queue>
> #include <cstring>
> using namespace std;
> int main(){
>     printf("(0, 0)\n");
>      cout<<"(1, 0)"<<endl;
>      cout<<"(2, 0)"<<endl;
>       cout<<"(2, 1)"<<endl;
>     cout<<"(2, 2)"<<endl;
> cout<<"(2, 3)"<<endl;
> cout<<"(2, 4)"<<endl;
> cout<<"(3, 4)"<<endl;
> cout<<"(4, 4)"<<endl;
> }