var suma,produs:byte;
    t,i:longint;
    s:string;
    f,g:text;

procedure calculprodus(var produs:byte;nr1,p1,p2:longint);
begin
if nr1<p1 then
 begin
 inc(nr1);
 produs:=p1*p2;
 p2:=produs mod 10;
 calculprodus(produs,nr1,p1,p2);
 end;
end;

procedure adunare(s:string;var suma:byte);
var j,nr,e:longint;
begin
val(s,nr,e);
for j:=1 to nr do
 begin
 produs:=1;
 calculprodus(produs,1,j,j);
 suma:=suma mod 10 + produs mod 10;
 end;
end;

begin
assign(f,'cifra.in');
reset(f);
assign(g,'cifra.out');
rewrite(g);
readln(f,t);
for i:=1 to t do
 begin
 readln(f,s);
 suma:=0;
 adunare(s,suma);
 writeln(g,suma mod 10);
 end;
close(f);
close(g);
end.