program alex;
var f,g:text;
    s:string;
    er:integer;
    i,j,t,un,z,x,k,u:longint;
    a,r:array[0..15,0..15]of integer;

begin
assign(g,'cifra.out');rewrite(g);
assign(f,'cifra.in');reset(f);
readln(f,t);
for i:=0 to 9 do
    for j:=0 to 9 do
        begin
        x:=i*10+j;
        a[i,j]:=((x div 20)*4)mod 10;
        r[i,j]:=x mod 20;
        end;
for i:=1 to t do
    begin
    readln(f,s);
    k:=length(s);
    val(s[k],un,er);
    val(s[k-1],z,er);
    u:=a[z,un];
    case r[z,un] of
    1,17:u:=u+1;
    2,18:u:=u+5;
    3,7:u:=u+2;
    4,8,11,15:u:=u+8;
    5,14:u:=u+3;
    6:u:=u+9;
    9,10,13:u:=u+7;
    12,16,19:u:=u+4;
    end;
    u:=u mod 10;
    writeln(g,u);
    end;
close(f);
close(g);
end.