/*???????????????????????*/

/*include???*/

/*??????*/
struct node	
{
	int x;		//?????????
	struct node *pb;		//???????
	struct node *pn;		//???????
};

/*???????*/
void jianli (struct node *ph,int* f,int* w,struct node **pl)		//ph?????f???????pl?????????????
{
	char c;		//c???????
	*f=1;		//f????????1?????-1????????1
	*w=1;		//w???????????1
	struct node *p,*q;		//?????????????
	c=getchar();		//???????
	//?????????
	if (c=='-')
	{
		*f=-1;		//???????
		c=getchar();		//??????????????
	}
	q=ph;		//????????q
	//?????0
	if (c=='0')
	{
		for (;;)		//??????????0??
		{
			if (c!='0')			//??0??
				break;
			else		//???0?????
				c=getchar();
		}
		if ((c<'0')||(c>'9'))		//??c???0??????????????0???????????????0?????
		{
			p=(struct node*)malloc(sizeof(struct node));		//??????????????
			p->pn=q->pn;
			p->pb=q;
			q->pn=p;
			q=p;
			p->x=0;		//?????0
			*w=1;		//????????
			*pl=p;		//?????????????????
			return;		//????
		}
	}
	//??????0??????????????
	for (;;)
	{
		if ((c<'0')||(c>'9'))		//???????????
		{
			*pl=p;		//?????????????????
			return;		//????
		}
		p=(struct node*)malloc(sizeof(struct node));		//???????????????
		p->pn=q->pn;
		p->pb=q;
		q->pn=p;
		q=p;
		p->x=c-'0';		//????????
		*w=*w+1;		//??+1
		c=getchar();		//?????????
	}
}

/*????*/
void shanchu (struct node *ph)		//ph????????
{
	struct node *p,*q;		//?????????????
	p=ph;		//????????p
	//?????????????????
	for (;;)
	{
		if (p==NULL)		//?????????????????
			return;
		q=p->pn;		//?????????
		free(p);		//????
		p=q;		//???????????
	}
}

/*???????????*/
void jia (struct node *pl1,struct node *pl2,struct node *p3)		//p3??????????pl1?pl2??????????????
{
	struct node *a,*b,*p,*r;		//?????????????
	int c,j=0;		//c????????????j???????0??????1????
	a=pl1;		//a?b??????????????????????
	b=pl2;
	//?????????
	for (;;)
	{
		if ((a->pb==NULL)&&(b->pb==NULL))		//???????????????
		{
			if (j==1)		//????????????????????p3?????????1???
			{
				p=(struct node*)malloc(sizeof(struct node));		//???????????????
				p->pn=p3->pn;
				p->pb=p3;
				p3->pn=p;
				p->x=1;		//?????1
			}
			return;
		}
		//????????????????????????????
		else if (a->pb==NULL)
		{
			r=a;
			a=b;
			b=r;
		}
		//?????????????????????????
		if (b->pb==NULL)
		{
			c=a->x+j;		//????????????????
			j=0;		//??j
			if (c>9)		//???????c?10????????
			{
				j=1;
				c=c-10;
			}
			p=(struct node*)malloc(sizeof(struct node));		//???????????????
			p->pn=p3->pn;
			p->pb=p3;
			p3->pn=p;
			p->x=c;		//???????
			a=a->pb;		//??????????
			continue;		//??????????
		}
		c=a->x+b->x+j;		//????????????????
		j=0;		//??j
		if (c>9)		//???????c?10????????
		{
			j=1;
			c=c-10;
		}
		p=(struct node*)malloc(sizeof(struct node));		//???????????????
		p->pn=p3->pn;
		p->pb=p3;
		p3->pn=p;
		p->x=c;		//???????
		a=a->pb;		//??????????
		b=b->pb;
	}
}

/*???????????*/
void jian (struct node *pl1,struct node *pl2,struct node *p3)		//p3??????????pl1?pl2???????????????pl1??????pl2????
{
	struct node *a,*b,*p,*r;		//?????????????
	int c,j=0;		//c????????????j???????0??????1????
	a=pl1;		//a?b??????????????????????
	b=pl2;
	//?????????
	for (;;)
	{
		if ((a->pb==NULL)&&(b->pb==NULL))		//???????????????
		{
			return;
		}
		//???????????????????
		if (b->pb==NULL)
		{
			c=a->x-j;		//????????????????
			j=0;		//??j
			if (c<0)		//???????c?10??????????
			{
				j=1;
				c=c+10;
			}
			p=(struct node*)malloc(sizeof(struct node));		//???????????????
			p->pn=p3->pn;
			p->pb=p3;
			p3->pn=p;
			p->x=c;		//???????
			a=a->pb;		//??????????
			continue;		//??????????
		}
		c=(a->x)-(b->x)-j;		//????????????????
		j=0;		//??j
		if (c<0)		//???????c?10??????????
		{
			j=1;
			c=c+10;
		}
		p=(struct node*)malloc(sizeof(struct node));		//???????????????
		p->pn=p3->pn;
		p->pb=p3;
		p3->pn=p;
		p->x=c;		//???????
		a=a->pb;		//??????????
		b=b->pb;
	}
}

/*????*/
void shuchu (struct node *p3,int f)		//p3?????????f??????????
{
	struct node *p;		//?????????????
	p=p3->pn;		//??????????????????????
	//?????????0??????
	for (;;)
	{
		if ((p==NULL)||(p->x!=0))		//?????????????????????0?????
			break;
		else
			p=p->pn;		//???0??????
	}
	//??????0?????0
	if (p==NULL)
		printf("0\n");
	//????????
	else
	{
		if (f==-1)		//???????????
			printf("-");
		for (;;)		//???????????
		{
			if (p==NULL)		//???????????????
			{
				printf("\n");
				break;
			}
			else		//????????
			{
				printf("%d",p->x);		//??????????
				p=p->pn;		//?????
			}
		}
	}
}

/*???????????????*/
int bijiao (struct node *p1,struct node *p2,int w1,int w2)		//p1,p2?????????w1,w2????????????????????????????????????????????0
{
	struct node *a,*b;		//?????????????
	//?????
	if (w1!=w2)		//?????????????
		return w1-w2;
	else		//???????????????
	{
		a=p1->pn;		//??????????????????????
		b=p2->pn;
		for (;;)
		{
			if (a==NULL)		//?????????????????????????????0
				return 0;
			if ((a->x)!=(b->x))		//????????????????????
				return (a->x)-(b->x);
			else		//?????????????????
			{
				a=a->pn;
				b=b->pn;
			}
		}
	}
}

/*???*/
int main ()
{
	int f1,f2,w1,w2,f;		//f1?f2?????????????1????-1?f????????????w1?w2?????????
	//???????????????????????p1?p2??????p3???
	struct node *p1=(struct node*)malloc(sizeof(struct node));
	struct node *p2=(struct node*)malloc(sizeof(struct node));
	struct node *p3=(struct node*)malloc(sizeof(struct node));
	struct node *pl1,*pl2,*p;		//pl1?pl2???????????p???????????
	//???????
	p1->pn=NULL;
	p2->pn=NULL;
	p3->pn=NULL;
	p1->pb=NULL;
	p2->pb=NULL;
	p3->pb=NULL;
	//??????
	//printf("???????????????");
	jianli(p1,&f1,&w1,&pl1);		//????????p1??????????????????
	//printf("???????????????");
	jianli(p2,&f2,&w2,&pl2);		//????????p1??????????????????
	//printf("???????????????");
	//?????
	if (f1*f2==1)		//???????????????????p3?????
	{
		jia (pl1,pl2,p3);
		shuchu (p3,f1);
	}
	else		//??????????????????????????????????????????
	{
		if (bijiao (p1,p2,w1,w2)==0)		//????????????????????0
			printf("0\n");
		else
		{
			if (bijiao (p1,p2,w1,w2)<0)		//????????????????
			{
				f=f1;		//????
				f1=f2;
				f2=f;
				p=p1;		//?????
				p1=p2;
				p2=p;
				p=pl1;		//???????
				pl1=pl2;
				pl2=p;
			}
			jian (pl1,pl2,p3);		//????????????????p3?????
			shuchu (p3,f1);
		}
	}
	//????
	shanchu(p1);
	shanchu(p2);
	shanchu(p3);
	//????
	return 0;
}