defmodule Main do

    def in_range(a, b, day) do
        case (b < day || a > day) do
            true -> 1
            _ -> 0
        end
    end

    def solve(a, b) do
        List.foldl([23, 24, 25], 0, fn(x, acc) -> acc + in_range(a, b, x) end)
    end

    def main do
        [a, b] = IO.gets("") |> String.trim |> String.split |> Enum.map(&String.to_integer/1)
        solve(a, b) |> IO.puts
    end
end