program cifre;
var f,g:text;
        s,p,i,t,j,n:word;
begin
        assign(f,'cifre.in');
        assign(g,'cifre.out');
        reset(f);
        rewrite(g);
        read(f,t);
        s:=0;
        for i:=1 to t do
        begin
                readln(f,n);
                for j:=1 to n do
                begin
                        case (j mod 4) of
                        0:p:=(j mod 4)*(j mod 4)*(j mod 4)*(j mod 4);
                        1:p:=(j mod 4);
                        2:p:=(j mod 4)*(j mod 4);
                        3:p:=(j mod 4)*(j mod 4)*(j mod 4);
                        end;
                s:=(s+p) mod 10;
                end;
        end;
        writeln(g,s);
        close(f);
        close(g);
end.