public int recursion(List<Integer> currentNodes, int end) {
        List<Integer> nextNodes = new ArrayList<>();
        for (int current : currentNodes) {
            List<int[]> connectingNodes = connections.get(current - 1);
            Iterator<int[]> iter = connectingNodes.iterator();
            while (iter.hasNext() && cont) {
                int[] connectingNode = iter.next();
                int number = connectingNode[0];
                int length = connectingNode[1] + distanceTo.get(current) + connectingNodes.size();
                if (!distanceTo.containsKey(number)
                        || distanceTo.get(number) > length) {
                    distanceTo.put(number, length);
                    nextNodes.add(number);
                }
            }
        }

        if (getMinDistance(nextNodes) > distanceTo.get(end)
                || currentNodes.isEmpty()) {
            if (distanceTo.get(end) == max) return -1;
            return distanceTo.get(end);
        }

        return recursion(nextNodes, end);
    }