program cifra;
var n,j,k,l,e,i,p,s,m :longint;
var x,t :string;
var f,ff :text;
function h(g :longint) : longint;
begin
p:=1;
s:=0;
repeat
s:=s+1;
p:=p*g;
p:=p mod 10;
until s=g;
h:=p;
end;
function u(c :longint) : longint;
begin
i:=0;
m:=0;
for i:=1 to c do
begin
m:=m+h(i);
end;
u:=m mod 10;
end;
begin
assign(f,'cifra.in');
reset(f);
assign(ff,'cifra.out');
rewrite(ff);
readln(f,n);
for k:=1 to n do
begin
readln(f,x);
t:='';
if length(x)>1 then
t:=t+x[length(x)-1];
t:=t+x[length(x)];
val(t,l,e);
writeln(ff,u(l));
end;
close(f);
close(ff);
end.