#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>
#define MAX 300


void rev(char *from,char *to)
{
    int len,i;
    len=strlen(from);
    for(i=0;i<len;i++)
	to[i]=from[len-i-1];
    to[len]='\0';
}

void add(char *first,char *sec,char *result)
{
    char F[MAX],S[MAX],R[MAX];
    int flen,slen,now,extra,sum;
    flen=strlen(first);
    slen=strlen(sec);
    rev(first,F);
    rev(sec,S);
    for(now=0,extra=0;(now<flen&&now<slen);now++)
    {
	sum=(F[now]-'0')+(S[now]-'0')+extra;
	R[now]=sum%10+'0';
	extra=sum/10;
    }
    for(;now<flen;now++)
    {
	 sum=F[now]+extra-'0';
	R[now]=sum%10+'0';
	extra=sum/10;

    }

     for(;now<slen;now++)
    {
	 sum=S[now]+extra-'0';
	R[now]=sum%10+'0';
	extra=sum/10;

    }
    if(extra!=0)
	R[now++]=extra+'0';
    R[now]='\0';
    if(strlen(R)==0)
	strcpy(R,"0");
    rev(R,result);

}

int main()
{
    static char f[MAX],s[MAX],r[MAX];
    int i,len,t=0;
    while(gets(f)!=NULL)
    {
	if(t==0)
	{
	       t++;
	       strcpy(s,f);
	}
	else if(f[0]=='0')
		break;
	else{

	add(f,s,r);
	strcpy(s,r);
	}

    }
	len=strlen(r);
	for(i=0;i<len;i++)
	    printf("%c",r[i]);
        printf("\n");


    return 0;
}