#define F for(i=*++v;*++i;);for(y=k+1;i-*v;)*--y+=*--i-48
char*i,s[999],c,*k=s+500,*y;main(int C,char**v){F;F;for(;k>s;c=*k>9,*k---=10*c-48)if(*k+=c)y=k;puts(y);return 0;}