var n,i,l,j,c,x,y,t:integer;
    f,g:text;
begin
assign(f,'cifra.in');reset(f);
assign(g,'cifra.out');rewrite(g);
readln(f,T);
for l:=1 to T do
    begin
    readln(f,n);
    x:=0;
    for i:=1 to n do
        begin    y:=i; c:=i mod 10 ;
        for j:=1 to y-1 do
            begin
            c:=y*c;
            c:=c mod 10;
            end;
        x:=x+c;
        x:=x mod 10;
        end;
writeln(g,x);
    end;
close(f);close(g);
end.