If this is what you got so far:
InputStream letturaEasy = getResources().openRawResource(R.raw.max_easy);
Then all that needs to be done is to convert that to a String:
String result = getStringFromInputStream(letturaEasy);
And finally, to int:
int num = Integer.parseInt(result);
By the way, getStringFromInputStream() was implemented here:
private static String getStringFromInputStream(InputStream is) {
    BufferedReader br = null;
    StringBuilder sb = new StringBuilder();
    String line;
    try {
        br = new BufferedReader(new InputStreamReader(is));
        while ((line = br.readLine()) != null) {
            sb.append(line);
        }
    } catch (IOException e) {
        e.printStackTrace();
    } finally {
        if (br != null) {
            try {
                br.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
    return sb.toString();     
}