private static boolean checkAll(int arrIdx, int ch, int charIdx) {
		int errCnt = 0;
		for (int j = 0; j < cts.length; j++) {
			if (j == arrIdx || ct[j].length <= charIdx)
				continue;
			int x = (ch ^ ct[j][charIdx]);
			if (x == 0)
				continue;
			if (!((x >= 'A' && x <= 'Z') || (x >= 'a' && x <= 'z'))) {
				errCnt++;
				if (errCnt > 2)
					return false;
			}
		}
		return true;
	}