Buggy python submission (verdict: Runtime Error):
from collections import defaultdict

N, K = map(int, input().split())
A = list(map(int, input().split()))

D = defaultdict(list)

for i in range(N):
    D[A[i]].append(i)

next = [None for _ in range(N)]
dist = [None for _ in range(N)]

for v in D.values():
    l = len(v)
    for i in range(l):
        next[v[i]] = (v[(i + 1) % l] + 1) % N
        dist[v[i]] = (v[(i + 1) % l] - v[i] + N - 1) % N + 2

period = 0
node = 0

while node or not period:
    period += dist[node]
    node = next[node]

rem = N * K % period
count = 0
node = 0

while count + dist[node] <= rem:
    count += dist[node]
    node = next[node]

s = []
used = [0 for _ in range(max(A))]

for i in range(rem - count):
    j = (node + i) % N
    if not used[A[j] - 1]:
        used[A[j] - 1] = 1
        s.append(A[j])
    else:
        used[A[j] - 1] = 0
        while True:
            p = s.pop()
            if p == A[j]:
                break

print(*s)

Fixed submission:
from collections import defaultdict

N, K = map(int, input().split())
A = list(map(int, input().split()))

D = defaultdict(list)

for i in range(N):
    D[A[i]].append(i)

next = [None for _ in range(N)]
dist = [None for _ in range(N)]

for v in D.values():
    l = len(v)
    for i in range(l):
        next[v[i]] = (v[(i + 1) % l] + 1) % N
        dist[v[i]] = (v[(i + 1) % l] - v[i] + N - 1) % N + 2

period = 0
node = 0

while node or not period:
    period += dist[node]
    node = next[node]

rem = N * K % period
count = 0
node = 0

while count + dist[node] <= rem:
    count += dist[node]
    node = next[node]

s = []
used = [0 for _ in range(10**6)]

for i in range(rem - count):
    j = (node + i) % N
    if not used[A[j] - 1]:
        used[A[j] - 1] = 1
        s.append(A[j])
    else:
        while True:
            p = s.pop()
            used[p - 1] = 0
            if p == A[j]:
                break

print(*s)

Buggy python submission (verdict: Runtime Error):
from collections import defaultdict

N, K = map(int, input().split())
A = list(map(int, input().split()))

D = defaultdict(list)

for i in range(N):
    D[A[i]].append(i)

next = [None for _ in range(N)]
dist = [None for _ in range(N)]

for v in D.values():
    l = len(v)
    for i in range(l):
        next[v[i]] = (v[(i + 1) % l] + 1) % N
        dist[v[i]] = (v[(i + 1) % l] - v[i] + N - 1) % N + 2

period = 0
node = 0

while node or not period:
    period += dist[node]
    node = next[node]

rem = N * K % period
count = 0
node = 0

while count + dist[node] <= rem:
    count += dist[node]
    node = next[node]

s = []
used = [0 for _ in range(N)]

for i in range(rem - count):
    j = (node + i) % N
    if not used[A[j] - 1]:
        used[A[j] - 1] = 1
        s.append(A[j])
    else:
        used[A[j] - 1] = 0
        while True:
            p = s.pop()
            if p == A[j]:
                break

print(*s)

Fixed submission:
from collections import defaultdict

N, K = map(int, input().split())
A = list(map(int, input().split()))

D = defaultdict(list)

for i in range(N):
    D[A[i]].append(i)

next = [None for _ in range(N)]
dist = [None for _ in range(N)]

for v in D.values():
    l = len(v)
    for i in range(l):
        next[v[i]] = (v[(i + 1) % l] + 1) % N
        dist[v[i]] = (v[(i + 1) % l] - v[i] + N - 1) % N + 2

period = 0
node = 0

while node or not period:
    period += dist[node]
    node = next[node]

rem = N * K % period
count = 0
node = 0

while count + dist[node] <= rem:
    count += dist[node]
    node = next[node]

s = []
used = [0 for _ in range(10**6)]

for i in range(rem - count):
    j = (node + i) % N
    if not used[A[j] - 1]:
        used[A[j] - 1] = 1
        s.append(A[j])
    else:
        while True:
            p = s.pop()
            used[p - 1] = 0
            if p == A[j]:
                break

print(*s)