2dop

#include <iostream>
#include <cctype>
#include <cstring>
#include <iomanip>
#include <cmath>
using namespace std;

int main() {
    int n;
    cin >> n;
    int N = ceil(sqrt(n));
    //cout << N << endl;
    int arr[N][N];
    int count = 1;
    for (int j = 0; j < N; j++) {
        if (j%2 == 0) {
            for (int i = 0; i < N; i++) {
                if (count <= n) {
                    arr[i][j] = count;
                    count++;
                }
                else {
                    arr[i][j] = 0;
                }
            }
        }
        else {
            for (int i = N-1; i >= 0; i--) {
                if (count <= n) {
                    arr[i][j] = count;
                    count++;
                }
                else {
                    arr[i][j] = 0;
                }
            }
        }
    }
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            cout << arr[i][j] << " ";
        }
        cout << endl;
    }
}