let () =
  let m = Char.code 'z' - Char.code 'a' + 1 in
  let s = Array.make m 0 in
  let t = Array.make m 0 in
  let a, b = Scanf.scanf "%s %s " (fun a b -> a, b) in
  let to_n c = Char.code c - Char.code 'a' in
  let l = String.length a in
  let doit c z =
    for i = 0 to l - 1 do
      let x = to_n c.[i] in
      z.(x) <- z.(x) + 1;
    done in
  doit a s;
  doit b t;
  let rec doit i =
    if i = m then "YES"
    else if s.(i) <> t.(i) then "NO"
    else doit (i + 1) in
  doit 0 |> print_endline