program cifra;
var b:array[0..30000]of integer;
a:array[0..4,0..9]of integer;
i,j,k,s,n,t:integer;
f,g:text;
begin
assign(f,'cifra.in');
reset(f);
assign(g,'cifra.out');
rewrite(g);
readln(f,t);
for i:=1 to t do
read (f,b[i]);
read(f,b[i]);
for i:=1 to 4 do
for j:=0 to 9 do begin
a[i,j]:=1;
for k:=1 to i do
a[i,j]:=(a[i,j]*j mod 10);
end;
a[0]:=a[4];
for i:=1 to t do begin
s:=0;
for j:=1 to b[i] do
s:=(s+a[j mod 4,j mod 10])mod 10;
writeln(g,s);
end;
close(f);
close(g);
end.