tj

#include<bits/stdc++.h>
using namespace std;

int main()
{
    int a;
    cin>>a;
    for(int i = 0;i<a;i++){
        for(int j = 1;j<a+1;j++)
            {
            if(i%2==0)
                cout<<j+i*a<<" ";
            else
                cout<<(i+1)*a-j+1<<" ";
            }
        cout<<endl;
}
}