Buggy python submission (verdict: Runtime Error):
N, K = map(int, input().split())
P = list(map(int, input().split()))
C = list(map(int, input().split()))
c = [1] * N
m = [[0] * (N+1) for i in range(N)]
for i in range(N):
    m[i][1] = (C[P[i]-1])
for i in range(N):
    j = i
    while P[j]-1 != i:
        j = P[j]-1
        c[i] += 1
        m[i][c[i]] = m[i][c[i]-1] + C[P[j]-1]
ans = max(C)
for i in range(N):
    if m[i][c[i]] > 0:
        if  m[i][c[i]] * (K//c[i]) + max(m[i][1:K%c[i]+1]) > ans:
            ans = m[i][c[i]] * (K//c[i]) + max(m[i][1:K%c[i]+1])
    else:
        if max(m[i][1:min(c[i],K)+1]) > ans:
            ans = max(m[i][1:min(c[i],K)+1])
print(ans)


Fixed submission:
N, K = map(int, input().split())
P, C = [list(map(int, input().split())) for _ in range(2)]
c = [1] * N
m = [[0] * (N+1) for i in range(N)]
for i in range(N):
    m[i][1] = (C[P[i]-1])
ans = max(C)
for i in range(N):
    j = i
    while P[j]-1 != i:
        j = P[j]-1
        c[i] += 1
        m[i][c[i]] = m[i][c[i]-1] + C[P[j]-1]
    if m[i][c[i]] > 0:
        ans = max(ans, m[i][c[i]] * (K//c[i]-1) + max(m[i] + [m[i][c[i]] + m[i][j+1] for j in range(K%c[i])]))
    else:
        ans = max(ans, max(m[i][1:min(c[i],K)+1]))
print(ans)

Buggy python submission (verdict: Runtime Error):
N, K = map(int, input().split())
P = list(map(int, input().split()))
C = list(map(int, input().split()))
c = [1] * N
s = [C[P[i]-1] for i in range(N)]
m = [[0] * (N+1) for i in range(N)]
for i in range(N):
    m[i][1] = (C[P[i]-1])
for i in range(N):
    j = i
    while P[j]-1 != i:
        j = P[j]-1
        c[i] += 1
        s[i] += C[P[j]-1]
        if  c[i] <= K:
            if s[i] > m[i][c[i]-1]:
                m[i][c[i]] = s[i]
            else:
                m[i][c[i]] = m[i][c[i]-1]
print(c)
print(s)
print(m)
ans = max(C)
for i in range(N):
    if s[i] > 0:
        print(s[i] * (K//c[i]) + m[i][K%c[i]])
        if  s[i] * (K//c[i]) + m[i][K%c[i]] > ans:
            ans = s[i] * (K//c[i]) + m[i][K%c[i]]
    else:
        print(max(m[i][1:min(c[i]+1,K+1)]))
        if m[i][min(c[i],K)] > ans:
            ans = m[i][min(c[i],K)]
print(ans)


Fixed submission:
N, K = map(int, input().split())
P, C = [list(map(int, input().split())) for _ in range(2)]
c = [1] * N
m = [[0] * (N+1) for i in range(N)]
for i in range(N):
    m[i][1] = (C[P[i]-1])
ans = max(C)
for i in range(N):
    j = i
    while P[j]-1 != i:
        j = P[j]-1
        c[i] += 1
        m[i][c[i]] = m[i][c[i]-1] + C[P[j]-1]
    if m[i][c[i]] > 0:
        ans = max(ans, m[i][c[i]] * (K//c[i]-1) + max(m[i] + [m[i][c[i]] + m[i][j+1] for j in range(K%c[i])]))
    else:
        ans = max(ans, max(m[i][1:min(c[i],K)+1]))
print(ans)

Buggy python submission (verdict: Runtime Error):
N, K = map(int, input().split())
P = list(map(int, input().split()))
C = list(map(int, input().split()))
c = [1] * N
s = [C[P[i]-1] for i in range(N+1)]
m = [[0] * (N+1) for i in range(N)]
for i in range(N):
    m[i][1] = (C[P[i]-1])
for i in range(N):
    j = i
    while P[j]-1 != i:
        j = P[j]-1
        c[i] += 1
        s[i] += C[P[j]-1]
        if  c[i] <= K:
            if s[i] > m[i][c[i]-1]:
                m[i][c[i]] = s[i]
            else:
                m[i][c[i]] = m[i][c[i]-1]
ans = min(C)
for i in range(N):
    if s[i] > 0:
        if  s[i] * (K//c[i]) + m[i][K%c[i]] > ans:
            ans = s[i] * (K//c[i]) + m[i][K%c[i]]
    else:
        if max(m[i][1:min(c[i],K+1)]) > ans:
            ans = max(m[i][1:min(c[i],K+1)])
print(ans)


Fixed submission:
N, K = map(int, input().split())
P, C = [list(map(int, input().split())) for _ in range(2)]
c = [1] * N
m = [[0] * (N+1) for i in range(N)]
for i in range(N):
    m[i][1] = (C[P[i]-1])
ans = max(C)
for i in range(N):
    j = i
    while P[j]-1 != i:
        j = P[j]-1
        c[i] += 1
        m[i][c[i]] = m[i][c[i]-1] + C[P[j]-1]
    if m[i][c[i]] > 0:
        ans = max(ans, m[i][c[i]] * (K//c[i]-1) + max(m[i] + [m[i][c[i]] + m[i][j+1] for j in range(K%c[i])]))
    else:
        ans = max(ans, max(m[i][1:min(c[i],K)+1]))
print(ans)

Buggy python submission (verdict: Runtime Error):
N, K = map(int, input().split())
P = list(map(int, input().split()))
C = list(map(int, input().split()))
c = [1] * N
s = [C[P[i]-1] for i in range(N)]
m = [[0] * (N+1) for i in range(N)]
for i in range(N):
    m[i][1] = (C[P[i]-1])
for i in range(N):
    j = i
    while P[j]-1 != i:
        j = P[j]-1
        c[i] += 1
        s[i] += C[P[j]-1]
        if  c[i] <= K:
            if s[i] > m[i][c[i]-1]:
                m[i][c[i]] = s[i]
            else:
                m[i][c[i]] = m[i][c[i]-1]
print(c)
print(s)
print(m)
ans = min(C)
for i in range(N):
    if s[i] > 0:
        if  s[i] * (K//c[i]) + m[i][K%c[i]] > ans:
            ans = s[i] * (K//c[i]) + m[i][K%c[i]]
    else:
        if max(m[i][1:c[i]]) > ans:
            ans = max(m[i][1:c[i]])
print(ans)


Fixed submission:
N, K = map(int, input().split())
P, C = [list(map(int, input().split())) for _ in range(2)]
c = [1] * N
m = [[0] * (N+1) for i in range(N)]
for i in range(N):
    m[i][1] = (C[P[i]-1])
ans = max(C)
for i in range(N):
    j = i
    while P[j]-1 != i:
        j = P[j]-1
        c[i] += 1
        m[i][c[i]] = m[i][c[i]-1] + C[P[j]-1]
    if m[i][c[i]] > 0:
        ans = max(ans, m[i][c[i]] * (K//c[i]-1) + max(m[i] + [m[i][c[i]] + m[i][j+1] for j in range(K%c[i])]))
    else:
        ans = max(ans, max(m[i][1:min(c[i],K)+1]))
print(ans)