Отбор 7.27

var
  a: array [1..9] of integer;
  i, n, t, min, first: integer;

begin
  first := 0;
  readln(n);
  min := n;
  for i := 1 to 9 do
    a[i] := 0;
  for i := 1 to n do
  begin
    readln(t);
    while (t > 0) do
    begin
      first := t mod 10;
      t := t div 10;
    end;
    a[first] := a[first] + 1;
  end;
  for i := 1 to n do
  begin
    if (a[i] <> 0) and (a[i] < min) then begin
      min := a[i];
      first := i;
    end;
  end;
  writeln(first);
end.