Buggy python submission (verdict: Time Limit Exceeded):
import sys
sys.setrecursionlimit(10**6)

n,m = map(int,input().split())

global clasta
clasta = [-1 for i in range(n)]
path = [[] for i in range(n)]
used = [0 for i in range(n)]
for _ in range(m):
    x,y,z = map(int,input().split())
    path[x-1].append(y-1)
    path[y-1].append(x-1)

def dfs(now,color):
    for y in path[now]:
        if clasta[y] == -1:
            clasta[y] = color
            dfs(y,color)
            
ans = 0
for idx,i in enumerate(clasta):
    if i == -1:
        clasta[idx] = idx
        if path[idx]:
            dfs(idx,idx)
        ans += 1

print(ans)

Fixed submission:
import sys
sys.setrecursionlimit(10**6)

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n

    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)

        if x == y:
            return

        if self.parents[x] > self.parents[y]:
            x, y = y, x

        self.parents[x] += self.parents[y]
        self.parents[y] = x

    def size(self, x):
        return -self.parents[self.find(x)]

    def same(self, x, y):
        return self.find(x) == self.find(y)

    def members(self, x):
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]

    def group_count(self):
        return len(self.roots())

    def all_group_members(self):
        return {r: self.members(r) for r in self.roots()}

    def __str__(self):
        return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots())
        
        
n,m = map(int,input().split())

uf = UnionFind(n)
for _ in range(m):
    x,y,z = map(int,input().split())
    uf.union(x-1, y-1)
    
print(uf.group_count())

Buggy python submission (verdict: Runtime Error):


n,m = map(int,input().split())

global clasta
clasta = [-1 for i in range(n)]
path = [[] for i in range(n)]
for _ in range(m):
    x,y,z = map(int,input().split())
    path[x-1].append(y-1)
    path[y-1].append(x-1)

def dfs(now,color):
    for y in path[now]:
        if clasta[y] == -1:
            clasta[y] = color
            dfs(y,color)
ans = 0
for idx,i in enumerate(clasta):
    if i == -1:
        clasta[idx] = idx
        dfs(idx,idx)
        ans += 1

print(ans)

Fixed submission:
import sys
sys.setrecursionlimit(10**6)

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n

    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)

        if x == y:
            return

        if self.parents[x] > self.parents[y]:
            x, y = y, x

        self.parents[x] += self.parents[y]
        self.parents[y] = x

    def size(self, x):
        return -self.parents[self.find(x)]

    def same(self, x, y):
        return self.find(x) == self.find(y)

    def members(self, x):
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]

    def group_count(self):
        return len(self.roots())

    def all_group_members(self):
        return {r: self.members(r) for r in self.roots()}

    def __str__(self):
        return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots())
        
        
n,m = map(int,input().split())

uf = UnionFind(n)
for _ in range(m):
    x,y,z = map(int,input().split())
    uf.union(x-1, y-1)
    
print(uf.group_count())

Buggy python submission (verdict: Time Limit Exceeded):
import sys
sys.setrecursionlimit(10**6)

n,m = map(int,input().split())

global clasta
clasta = [-1 for i in range(n)]
path = [[] for i in range(n)]
for _ in range(m):
    x,y,z = map(int,input().split())
    path[x-1].append(y-1)
    path[y-1].append(x-1)

def dfs(now,color):
    for y in path[now]:
        if clasta[y] == -1:
            clasta[y] = color
            dfs(y,color)

for idx,i in enumerate(clasta):
    if i == -1:
        clasta[idx] = idx
        dfs(idx,idx)

print(len(set(clasta)))

Fixed submission:
import sys
sys.setrecursionlimit(10**6)

class UnionFind():
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n

    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)

        if x == y:
            return

        if self.parents[x] > self.parents[y]:
            x, y = y, x

        self.parents[x] += self.parents[y]
        self.parents[y] = x

    def size(self, x):
        return -self.parents[self.find(x)]

    def same(self, x, y):
        return self.find(x) == self.find(y)

    def members(self, x):
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]

    def group_count(self):
        return len(self.roots())

    def all_group_members(self):
        return {r: self.members(r) for r in self.roots()}

    def __str__(self):
        return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots())
        
        
n,m = map(int,input().split())

uf = UnionFind(n)
for _ in range(m):
    x,y,z = map(int,input().split())
    uf.union(x-1, y-1)
    
print(uf.group_count())