Supply Chain Loop Detector

A factory produces various items. Each item might depend on other items to be manufactured. Given a list of dependencies, determine if item 0 is involved in any 'Infinite Loop' (a circular dependency) such that it could never be completed. Note that item 0 might not be directly in the loop, but it might depend on an item that is part of a loop. Input: The first line contains N (the number of items, 0 to N-1). The next N lines start with an item ID followed by K (number of dependencies) and then K space-separated item IDs that this item depends on. Output: Print 'LOOP' if item 0 is stalled by a circular dependency, otherwise 'SAFE'. Example: Input: 3 0 1 1 1 1 2 2 1 0 Output: LOOP