并查集朋友圈2

def solve(____):
    parent = {}
    def find(____):
        if x not in parent:
            parent[x] = x
        if parent[x] != x:
            parent[x] = find(____)
        return parent[x]
    for r in relations.split(____):
        a, b = r.split(____)
        pa, pb = find(____), find(____)
        parent[pa] = pb
    circles = len(set(find(____) for x in parent))
    print(____)