Buggy python submission (verdict: Runtime Error):
def get_articulation_points(G, N, start=0):
    v_min = [0]*N; order = [None]*N
    result = []; count = 0
    def dfs(v, prev):
        nonlocal count
        r_min = order[v] = count
        fcnt = 0; p_art = 0
        count += 1
        for w in G[v]:
            if w == prev:
                continue
            if order[w] is None:
                ret = dfs(w, v)
                p_art |= (ret == w)
                r_min = min(r_min, ret)
                fcnt += 1
            else:
                r_min = min(r_min, order[w])
        if (prev == -1 and fcnt > 1) or (prev != -1 and p_art):
            result.append(v)
        return r_min
    dfs(start, -1)
    return result

n, m = map(int, input().split())
G = [[] for i in range(n)]
for i in range(m):
    s, t = map(int, input().split())
    G[s].append(t)
    G[t].append(s)
[*map(print,sorted(get_articulation_points(G, n)))]

Fixed submission:
import sys
sys.setrecursionlimit(10**6)
readline = sys.stdin.readline
write = sys.stdout.write

N, M = map(int, readline().split())

G = [[] for i in range(N)]
for i in range(M):
    u, v = map(int, readline().split())
    G[u].append(v)
    G[v].append(u)

# a chain decomposition
def construct(G, N):
    P = [0]*N
    G0 = [[] for i in range(N)]
    V = []
    lb = [0]*N
    def dfs(v, p):
        P[v] = p
        V.append(v)
        lb[v] = len(V)
        for w in G[v]:
            if w == p:
                continue
            if lb[w]:
                if lb[v] < lb[w]:
                    # a backedge
                    G0[v].append(w)
                continue
            # a tree edge
            dfs(w, v)
    dfs(0, -1)

    used = [0]*N
    first = 1
    B = []
    used[0] = 1
    ap = [0]*N
    for u in V:
        if not used[u]:
            # (u, p) is a bridge
            p = P[u]
            B.append((u, p) if u < p else (p, u))
            if len(G[u]) > 1:
                ap[u] = 1
            if len(G[p]) > 1:
                ap[p] = 1
        cycle = 0
        for v in G0[u]:
            w = v
            while w != u and not used[w]:
                used[w] = 1
                w = P[w]
            if w == u:
                cycle = 1
        if cycle:
            if not first:
                ap[u] = 1
            first = 0
    # v is a cut vertex
    A = [v for v in range(N) if ap[v]]

    return B, A

B, A = construct(G, N)

for v in A:
    write("%d\n" % v)

Buggy python submission (verdict: Runtime Error):

def get_articulation_points(G, N, start=0):
    v_min = [0]*N; order = [None]*N
    result = []; count = 0
    def dfs(v, prev):
        nonlocal count
        r_min = order[v] = count
        fcnt = 0; p_art = 0
        count += 1
        for w in G[v]:
            if w == prev:
                continue
            if order[w] is None:
                ret = dfs(w, v)
                p_art |= (order[v] <= ret)
                r_min = min(r_min, ret)
                fcnt += 1
            else:
                r_min = min(r_min, order[w])
        p_art |= (r_min == order[v] and len(G[v]) > 1)
        if (prev == -1 and fcnt > 1) or (prev != -1 and p_art):
            result.append(v)
        return r_min
    dfs(start, -1)
    return result

n, m = map(int, input().split())
G = [[] for i in range(n)]
for i in range(m):
    s, t = map(int, input().split())
    G[s].append(t)
    G[t].append(s)
*_,=map(print,sorted(get_articulation_points(G, n)))

Fixed submission:
import sys
sys.setrecursionlimit(10**6)
readline = sys.stdin.readline
write = sys.stdout.write

N, M = map(int, readline().split())

G = [[] for i in range(N)]
for i in range(M):
    u, v = map(int, readline().split())
    G[u].append(v)
    G[v].append(u)

# a chain decomposition
def construct(G, N):
    P = [0]*N
    G0 = [[] for i in range(N)]
    V = []
    lb = [0]*N
    def dfs(v, p):
        P[v] = p
        V.append(v)
        lb[v] = len(V)
        for w in G[v]:
            if w == p:
                continue
            if lb[w]:
                if lb[v] < lb[w]:
                    # a backedge
                    G0[v].append(w)
                continue
            # a tree edge
            dfs(w, v)
    dfs(0, -1)

    used = [0]*N
    first = 1
    B = []
    used[0] = 1
    ap = [0]*N
    for u in V:
        if not used[u]:
            # (u, p) is a bridge
            p = P[u]
            B.append((u, p) if u < p else (p, u))
            if len(G[u]) > 1:
                ap[u] = 1
            if len(G[p]) > 1:
                ap[p] = 1
        cycle = 0
        for v in G0[u]:
            w = v
            while w != u and not used[w]:
                used[w] = 1
                w = P[w]
            if w == u:
                cycle = 1
        if cycle:
            if not first:
                ap[u] = 1
            first = 0
    # v is a cut vertex
    A = [v for v in range(N) if ap[v]]

    return B, A

B, A = construct(G, N)

for v in A:
    write("%d\n" % v)