def print_snake_matrix(n): # 初始化矩阵 matrix = [[0] * n for _ in range(n)] # 蛇形遍历矩阵 num = 1 for i in range(n): if i % 2 == 0: # 偶数行，从左到右填充 for j in range(n): matrix[i][j] = num num += 1 else: # 奇数行，从右到左填充 for j in range(n-1, -1, -1): matrix[i][j] = num num += 1 # 打印矩阵 for row in matrix: print(' '.join(f'{num:3}' for num in row)) # 输入矩阵的大小 n = int(input()) # 打印蛇形矩阵 print_snake_matrix(n)