NZEC in TOANDFRO

[thaitranbt]

Please help me to check it, I can't understand why I get NZEC in TO AND FRO spoj.pl/problems/TOANDFRO/

import java.util.Scanner;
class Do{
	private int h=0;
	Do(String a,int k){
		int kk=0;
		if (a.length()%k==0){
			 kk=a.length()/k;
		}
		else kk=a.length()/k+1;
		char[][] b=new char[kk+1][k+1];
		for (int i=1;i<=kk;i++){
			if (i%2==0){
				for (int j=k;j>=1;j--){
					if(h!=a.length()){
						b[i][j]=a.charAt(h);
						h++;
					}
					else b[i][j]=' ';
				}
			}
			else {
				for (int j=1;j<=k;j++){
					if(h!=a.length()){
						b[i][j]=a.charAt(h);
						h++;
					}
					else b[i][j]=' ';
				}
			}
		}
		for (int j=1;j<=k;j++){
		    for (int i=1;i<=kk;i++){
		    	if (b[i][j]!=' '){
		    		System.out.print(b[i][j]);
		    	}
		  }	
		}
	}
}
public class Main{
    /**
 * @param args
 */
public static void main(String[] args) {
	// TODO Auto-generated method stub
   Scanner sc= new Scanner(System.in);
   
   while (sc.hasNext()||sc.nextInt()!=0){
	   int dem=sc.nextInt();
	   String st=sc.next();
	   if ((st.equals("")==false) & (dem>=2)){
		   Do d= new Do(st,dem);
	   }
	   System.out.println();
   }
  
}
}

[thaitranbt]

When I change

 while (sc.hasNext()||sc.nextInt()!=0){
          int dem=sc.nextInt();
          String st=sc.next();
          if ((st.equals("")==false) & (dem>=2)){
             Do d= new Do(st,dem);
          }
          System.out.println();
       }

into

while (sc.hasNextLine()){
    	   int dem=sc.nextInt();
    	   if (dem==0){ 
    		   break;
    	   }
    	   else{
    	   String st=sc.next();
    	   if ((st.equals("")==false) & (dem>=2)){
    		   Do d= new Do(st,dem);
    	   }
    	   System.out.println();
       }

It 'll be accepted....I don't know why

[leppyr64]

Sc.nextInt() removes the next int from the buffer, regardless of whether you're storing the value or not.

While(sc.nextInt()!=0)
{
int x = sc.nextInt();
System.out.println(x);
}

Try that with input:
1
0
0

[thaitranbt]

Thanks,i see