Buggy python submission (verdict: Time Limit Exceeded):
n, m = map(int,input().split())

class unionfind():
    def __init__(self,n):
        self.li = [i for i in range(n+1)]
        self.group = [1]*(n+1)

    def find(self, x):
        while self.li[x]!=x:
            x = self.li[x]
        return x

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return;
        else:
            self.li[y] = x
            self.group[x] += self.group[y]
            self.group[y] = 1
x = unionfind(n)
ans = 0
for _ in range(m):
    a,b = map(int,input().split())
    x.union(a,b)
print(max(x.group))

Fixed submission:
n, m = map(int,input().split())

class unionfind():
    def __init__(self,n):
        self.li = [i for i in range(n+1)]
        self.group = [1]*(n+1)

    def find(self, x):
        while self.li[x]!=x:
            x = self.li[x]
        return x

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return;
        elif x>y:
            self.li[y] = x
            self.group[x] += self.group[y]
        else:
            self.li[x] = y
            self.group[y] += self.group[x]
x = unionfind(n)
ans = 0
for _ in range(m):
    a,b = map(int,input().split())
    x.union(a,b)
print(max(x.group))

Buggy python submission (verdict: Time Limit Exceeded):
n, m = map(int, input().split())
li = [0]*(n+1)
lii = []
flag = 1
for _ in range(m):
    a, b = map(int, input().split())
    if li[a] and li[b]:
        if li[a] != li[b]:
            lii.append([li[a], li[b]])
    elif li[a] or li[b]:
        s = max(li[a],li[b])
        li[a] = s
        li[b] = s
    else:
        li[a] = flag
        li[b] = flag
        flag += 1
for i in range(len(li)):
    if li[i] == 0:
        li[i] = -i
for i in lii:
    a,b = i[0],i[1]
    for j in range(len(li)):
        if li[j] == a or li[j] == b:
            li[j] = a+b
            
from collections import Counter
result = Counter(li)
print(result.most_common(1)[0][1])


Fixed submission:
n, m = map(int,input().split())

class unionfind():
    def __init__(self,n):
        self.li = [i for i in range(n+1)]
        self.group = [1]*(n+1)

    def find(self, x):
        while self.li[x]!=x:
            x = self.li[x]
        return x

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return;
        elif x>y:
            self.li[y] = x
            self.group[x] += self.group[y]
        else:
            self.li[x] = y
            self.group[y] += self.group[x]
x = unionfind(n)
ans = 0
for _ in range(m):
    a,b = map(int,input().split())
    x.union(a,b)
print(max(x.group))

Buggy python submission (verdict: Runtime Error):
n, m = map(int, input().split())
li = [0]*(n+1)
lii = []
flag = 1
for _ in range(m):
    a, b = map(int, input().split())
    if li[a] and li[b]:
        if li[a] != li[b]:
            lii.append(li[a],li[b])
    elif li[a] or li[b]:
        s = max(li[a],li[b])
        li[a] = s
        li[b] = s
    else:
        li[a] = flag
        li[b] = flag
        flag += 1
for i in range(len(li)):
    if li[i] == 0:
        li[i] = -i
    for j in lii:
        a,b = j
        if li[i] == a or li[i] == b:
            li[i] = a+b
from collections import Counter
result = Counter(li)
print(result.most_common(1)[0][1])


Fixed submission:
n, m = map(int,input().split())

class unionfind():
    def __init__(self,n):
        self.li = [i for i in range(n+1)]
        self.group = [1]*(n+1)

    def find(self, x):
        while self.li[x]!=x:
            x = self.li[x]
        return x

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return;
        elif x>y:
            self.li[y] = x
            self.group[x] += self.group[y]
        else:
            self.li[x] = y
            self.group[y] += self.group[x]
x = unionfind(n)
ans = 0
for _ in range(m):
    a,b = map(int,input().split())
    x.union(a,b)
print(max(x.group))

Buggy python submission (verdict: Time Limit Exceeded):
n, m = map(int, input().split())
li = [0]*(n+1)
flag = 1
for _ in range(m):
    a, b = map(int, input().split())
    if li[a] and li[b]:
        if li[a] != li[b]:
            x = li[b]
            for i in range(len(li)):
                if li[i] == x:
                    li[i] = li[a]
    elif li[a] or li[b]:
        s = max(li[a],li[b])
        li[a] = s
        li[b] = s
    else:
        li[a] = flag
        li[b] = flag
        flag += 1
for i in range(len(li)):
    if li[i] == 0:
        li[i] = -i
from collections import Counter
result = Counter(li)
print(result.most_common(1)[0][1])


Fixed submission:
n, m = map(int,input().split())

class unionfind():
    def __init__(self,n):
        self.li = [i for i in range(n+1)]
        self.group = [1]*(n+1)

    def find(self, x):
        while self.li[x]!=x:
            x = self.li[x]
        return x

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return;
        elif x>y:
            self.li[y] = x
            self.group[x] += self.group[y]
        else:
            self.li[x] = y
            self.group[y] += self.group[x]
x = unionfind(n)
ans = 0
for _ in range(m):
    a,b = map(int,input().split())
    x.union(a,b)
print(max(x.group))

Buggy python submission (verdict: Runtime Error):
n, m = map(int, input().split())
li = [0]*(n+1)
flag = 1
for _ in range(m):
    a, b = map(int, input().split())
    if li[a] and li[b]:
        if li[a]!=li[b]:
            x = li[b]
            for i in len(li):
                if li[i]==x:
                    li[i] = li[a]
    elif li[a] or li[b]:
        s = max(li[a],li[b])
        li[a] = s
        li[b] = s
    else:
        li[a] = flag
        li[b] = flag
        flag += 1
for i in range(len(li)):
    if li[i] == 0:
        li[i] = -i
from collections import Counter
result = Counter(li)
print(result.most_common(1)[0][1])

Fixed submission:
n, m = map(int,input().split())

class unionfind():
    def __init__(self,n):
        self.li = [i for i in range(n+1)]
        self.group = [1]*(n+1)

    def find(self, x):
        while self.li[x]!=x:
            x = self.li[x]
        return x

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return;
        elif x>y:
            self.li[y] = x
            self.group[x] += self.group[y]
        else:
            self.li[x] = y
            self.group[y] += self.group[x]
x = unionfind(n)
ans = 0
for _ in range(m):
    a,b = map(int,input().split())
    x.union(a,b)
print(max(x.group))