연결 요소의 개수.py

def find_parent(parent, x):
    if parent[x] != x:
        parent[x] = find_parent(parent, parent[x])
    return parent[x]

def union_parent(parent, a, b):
    a = find_parent(parent, a)
    b = find_parent(parent, b)
    if a < b :
        parent[b] = a
    else:
        parent[a] = b

n, m = map(int, input().split())
parent = [0] * (n+1)

for i in range(1, n+1):
    parent[i] = i

for j in range(m):
    u, v = map(int, input().split())
    union_parent(parent, u, v)

unique_parents = set()
for i in range(1, n + 1):
    unique_parents.add(find_parent(parent, i))
print(len(unique_parents))