public static void main(String[] args) {
	Scanner scanner = new Scanner(System.in);
	while(scanner.hasNext()) {
		int x = scanner.nextInt();
		int y = scanner.nextInt();
		if (x==0&&y==0) {
			scanner.close();
			break;
		}
		//scanner.nextLine();
		String a = "";
		for (int i = 0; i < x; i++) {
			a +=scanner.nextLine();
		}
		for (int i = 0; i < a.length(); i++) {
			if (i%y == 0) {
				System.out.println();
			}
			System.out.print(a.charAt(i));
			
		}
		
		}
}

/*用戶輸入：
 
  4空格4\n  	//遇到空格結(jié)束 x=4, 第二nextInt()遇到換行了結(jié)束它的掃描 y=4;
  			但是此行還沒有結(jié)束，nextLine會繼續(xù)掃描剩余部分直到換行，光標(biāo)才會進(jìn)入下一行
  			只不過剩余的是空字符串，記第一次nextLine()為a1,a1=""
  ****\n  	//a2 = "****",a2記第二次nextLine()
  ....\n  	//a3= "...."
  ....\n	//a4= "...."	
  ****\n	//此刻此行沒有對應(yīng)的nextline()，也就無法輸入了，接下就執(zhí)行打印輸出了。
  
  */

int x = scanner.nextInt();
		int y = scanner.nextInt();
		if (x==0&&y==0) {
			scanner.close();
			break;
		}
		scanner.nextLine();//用于緩沖換行符，換入新的一行。
		String a = "";
		for (int i = 0; i < x; i++) {
			a +=scanner.nextLine();
		}

Scanner scan = new Scanner(System.in);
?? ??? ?System.out.print("請輸入:");
?? ??? ?String year = scan.next();
?? ??? ?System.out.printf("%s",year);

Scanner scan = new Scanner(System.in);
System.out.print("請輸入:");
String year = scan.nextln();
System.out.printf("%s",year);

//useDelimiter("\n"); //“\n”換行符（回車）作為輸入的分隔符
Scanner scan = new Scanner(System.in).useDelimiter("\n");
System.out.print("請輸入:");
String year = scan.next();
System.out.printf("%s",year);