import java.util.Scanner;

public class Main {

	// 方向列舉
	enum Direction{
		DOWN, RIGHT_UP, RIGHT, LEFT_DOWN
	}
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int N, M;
		int[][] a;
		
		Scanner scan = new Scanner(System.in);
		N = scan.nextInt();		
		M = scan.nextInt();
		
		a = new int[N][M];
		for(int i = 0; i < N; i++) {
			for(int j = 0; j < M; j++) {
				a[i][j] = scan.nextInt();
			}
		}
		
		int row = 0, col = 0;
		Direction dir = Direction.DOWN;
		System.out.print(a[row][col] + " ");
		
		
		while(!(row == N - 1 && col == M - 1)) {
			
			switch(dir) {
				case DOWN:	// 向下走
					if(row < N - 1) {
						row++;
						System.out.print(a[row][col] + " ");
						if(col != M - 1) {
							dir = Direction.RIGHT_UP;
						} else {
							dir = Direction.LEFT_DOWN;
						}
					} else {
						dir = Direction.RIGHT;
					}
					break;
				case RIGHT_UP:	// 向右上方向走
					while(row > 0 && col < M - 1) {
						row--;
						col++;
						System.out.print(a[row][col] + " ");
					}
					
					if(row != 0) {
						dir = Direction.DOWN;
					} else {
						dir = Direction.RIGHT;
					}
					
					break;
				case RIGHT:	// 向右走
					if(col < M - 1) {
						col++;
						System.out.print(a[row][col] + " ");
						if(row != N - 1) {
							dir = Direction.LEFT_DOWN;
						} else {
							dir = Direction.RIGHT_UP;
						}
					} else {
						dir = Direction.DOWN;
					}
					
					break;
				case LEFT_DOWN: // 向左下方向走
					while(col > 0 && row < N - 1) {
						row++;
						col--;
						System.out.print(a[row][col] + " ");
					} 
					
					if(col != 0) {
						dir = Direction.DOWN;
					} else {
						dir = Direction.RIGHT;
					}
					
					break;
			}
			
		}
			
		
	}
	

	
}