#include<cstdio>
#include<string>
#define NMAX 103
#define FIN "cifra.in"
#define FOUT "cifra,out"
int v[]={0,1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0},t,l,c;
char s[NMAX];
int main()
{freopen(FIN,"r",stdin);
freopen(FOUT,"w",stdout);
scanf("%d",&t);
for(;t;t--)
 {gets(s);
  l=strlen(s);
  if(l-1==1) l=s[l-1]-48;
  else {l=(s[l-2]-48)*10+(s[l-1]-48);
        c=l/20;
        l=l%20;
        c=c*4;
       
       }
  for(int i=1;i<=l;i++)
   {c+=v[i];
          }
           }
  c=c%10;         
  printf("%d",c);         
    return 0;}