type vector=array[1..20] of string;
function putere(x,y:integer):longint;
begin
if y=0 then putere:=1
 else if odd(y) then putere:=x*putere(x,y-1)
  else putere:=sqr(putere(x,y div 2));
end;
procedure citire(var a:vector;var n:integer);
var f:text;
    i:integer;
begin
assign(f,'cifra.in');reset(f);
while not eof(f) do begin
read(f,n); readln(f);
for i:=1 to n do begin read(f,a[i]); readln(f);end;
end;
close(f);
end;
procedure afisare(a:vector;n:integer);
var i,c,x:integer;
    g:text;
    s:qword;
begin
assign(g,'cifra.out');rewrite(g);
s:=0;c:=0;
for i:=1 to n do begin
val(a[i][length(a[i])],c,x);
inc(s,putere(c,c));
writeln(g,s mod 10);
end;
close(g);
end;
var a:vector;
     n,i:integer;
begin
citire(a,n);
afisare(a,n);end.