Miscellany

vrt = substring(main, 12, 1) + substring(main, 1, 1) + substring(main, 12, 1) + substring(main, 15, 0) + substring(main, 20, 1) + substring(main, 21, 1) + substring(main, 19, 1) + substring(main, 1, 1) + substring(main, 23, 2);