> ///pku 1144 Newwork
> ////WA
> 
> #include<stdio.h>
> 
> typedef struct Node
> {
> 	bool visited;
> 	char value;
> 	struct Node *next;
> }* node;
> 
> char criticalnum=0;
> node a[101];
> int nodenum=0;
> bool find=false;
> bool iscriticalnode=false;
> 
> bool readin()  //if the last line 0,stop do,return false .Every time solve one block
> {
> 	int i;
> 	char ch;
> 	scanf("%d",&nodenum);
> 	i=nodenum;
> 	if(nodenum==0)
> 	{
> 		return false;
> 	}
> 
> 	for(i=0;i<=nodenum;i++)
> 	{
> 		a[i]=new struct Node;
> 		a[i]->visited=false;
> 		a[i]->value=i;
> 		a[i]->next=NULL;
> 	}
> 	getchar();   ////ignore the blank after the first line that expresses the nodenum
> 	while(i>0)
> 	{
> 		char first;
> 		i--;
> 		scanf("%c",&ch);
> 		if(ch=='0')
> 		{
> 			break;
> 		}
> 		first=ch-48;
> 	//	a[first]=new struct Node;
> 		a[first]->value=first;
> 		a[first]->next=NULL;
> 
> 		while(scanf("%c",&ch),ch!='\n')////read one line
> 		{
> 			if(ch==' ')
> 				continue;
> 			ch=ch-48;
> 			node temp,temp1;
> 			temp=new struct Node;
> 			temp->value=ch;
> 			temp->next=a[first]->next;
> 			a[first]->next=temp;
> 
> 			temp1=new struct Node;
> 			temp1->value=a[first]->value;
> 			temp1->next=a[ch]->next;
> 			a[ch]->next=temp1;
> 		}
> 	}
> 	return true;
> }
> 
> void CriticalNode(char num,char end,char remov)
> {
> 	if(find==true||a[num]->value==end)
> 	{
> 		find=true;
> 		return ;
> 	}
> 	if(num==remov)
> 	{
> 		return;
> 	}
> 
> 	node p=a[num]->next;
> 	a[num]->visited=true;
> 	while(p!=NULL)
> 	{
> 		if(a[p->value]->visited==false)
> 			CriticalNode(p->value,end,remov);
> 		p=p->next;
> 	}
> 
> }
> 
> void print()
> {
> 	for(int i=1;i<=nodenum;i++)
> 	{
> 		node p=a[i];
> 		while(p!=NULL)
> 		{
> 			printf("%d ",p->value);
> 			p=p->next;
> 		}
> 		printf("\n");
> 	}
> }
> 
> int main()
> {
> 	char i,j,k;
> 	
> 	while(readin())
> 	{
> 		
> 		
> 		criticalnum=0;
> 		for(k=1;k<=nodenum;k++)   ////remove k,see if it is critical node
> 		//	k=6;
> 		{
> 			for(int m=1;m<=nodenum;m++)
> 			{
> 				a[m]->visited=false;
> 			}
> 			iscriticalnode=false;
> 			find=false;
> 			for(i=1;i<=nodenum;i++)
> 			{
> 				for(int m=1;m<=nodenum;m++)
> 				{
> 					a[m]->visited=false;
> 				}
> 				if(i==k)
> 					continue;
> 				if(iscriticalnode==true)
> 					break;
> 				for(j=i+1;j<=nodenum;j++)
> 				{
> 					for(int m=1;m<=nodenum;m++)
> 					{
> 						a[m]->visited=false;
> 					}
> 
> 					if(j==k)
> 					{
> 						continue;
> 					}
> 					find=false;
> 					CriticalNode(i,j,k);
> 					if(find==false)
> 					{
> 						iscriticalnode=true;
> 						criticalnum++;
> 				//		printf("k=%d\n",k);
> 						break;
> 					}
> 
> 					
> 				}///end of for(j=i+1;j<=nodenum;j++)
> 
> 			}///end of for(i=1;i<=nodenum;i++)
> 			iscriticalnode=false;			 
> 		}////end of for k
> 		printf("%d\n",criticalnum);
> //		print();
> 	}
> 	return 0;
> }