Buggy python submission (verdict: Time Limit Exceeded):
import heapq as hq

X, Y, Z, K = map(int, input().split())
A = [int(i) for i in input().split()]
B = [int(i) for i in input().split()]
C = [int(i) for i in input().split()]

pri = []
data = []
hq.heapify(pri)

A.sort()
B.sort()
C.sort()
A.reverse()
B.reverse()
C.reverse()

hq.heappush(pri, [-A[0]-B[0]-C[0],0,0,0])
data.append([0,0,0])

for i in range(K):
    s = pri[0][1]
    t = pri[0][2]
    u = pri[0][3]
    if s+1 <= X-1:
        if [s + 1, t, u] not in data:
            data.append([s+1, t, u])
            hq.heappush(pri, [-A[s+1]-B[t]-C[u],s+1,t,u])
    if t+1 <= Y-1:
        if [s, t+1, u] not in data:
            data.append([s, t+1, u])
            hq.heappush(pri, [-A[s]-B[t+1]-C[u],s,t+1,u])
    if u+1 <= Z-1:
        if [s, t, u+1] not in data:
            data.append([s, t, u+1])
            hq.heappush(pri, [-A[s]-B[t]-C[u+1],s,t,u+1])
    print(hq.heappop(pri)[0] * -1)

Fixed submission:
import heapq as hq

X, Y, Z, K = map(int, input().split())
A = [int(i) for i in input().split()]
B = [int(i) for i in input().split()]
C = [int(i) for i in input().split()]

pri = []
data = []
hq.heapify(pri)

A.sort()
B.sort()
C.sort()
A.reverse()
B.reverse()
C.reverse()

hq.heappush(pri, [-A[0]-B[0]-C[0],0,0,0])
data.append([0,0,0])

for i in range(K):
    s = pri[0][1]
    t = pri[0][2]
    u = pri[0][3]
    if s+1 <= X-1:
        if [s + 1, t, u] not in data:
            data.append([s+1, t, u])
            hq.heappush(pri, [-A[s+1]-B[t]-C[u],s+1,t,u])
    if t+1 <= Y-1:
        if [s, t+1, u] not in data:
            data.append([s, t+1, u])
            hq.heappush(pri, [-A[s]-B[t+1]-C[u],s,t+1,u])
    if u+1 <= Z-1:
        if [s, t, u+1] not in data:
            data.append([s, t, u+1])
            hq.heappush(pri, [-A[s]-B[t]-C[u+1],s,t,u+1])
    print(hq.heappop(pri)[0] * -1)

Buggy python submission (verdict: Time Limit Exceeded):
X, Y, Z, K = map(int, input().split())
A = [int(i) for i in input().split()]
B = [int(i) for i in input().split()]
C = [int(i) for i in input().split()]

A.sort()
B.sort()
C.sort()
A.reverse()
B.reverse()
C.reverse()

data = []

for i in range(X):
    for j in range(Y):
        for k in range(Z):
            if i * j * k <= K:
                data.append(A[i] + B[j] + C[k])
                
data.sort()
data.reverse()
for i in range(K):
    print(data[i])

Fixed submission:
import heapq as hq

X, Y, Z, K = map(int, input().split())
A = [int(i) for i in input().split()]
B = [int(i) for i in input().split()]
C = [int(i) for i in input().split()]

pri = []
data = []
hq.heapify(pri)

A.sort()
B.sort()
C.sort()
A.reverse()
B.reverse()
C.reverse()

hq.heappush(pri, [-A[0]-B[0]-C[0],0,0,0])
data.append([0,0,0])

for i in range(K):
    s = pri[0][1]
    t = pri[0][2]
    u = pri[0][3]
    if s+1 <= X-1:
        if [s + 1, t, u] not in data:
            data.append([s+1, t, u])
            hq.heappush(pri, [-A[s+1]-B[t]-C[u],s+1,t,u])
    if t+1 <= Y-1:
        if [s, t+1, u] not in data:
            data.append([s, t+1, u])
            hq.heappush(pri, [-A[s]-B[t+1]-C[u],s,t+1,u])
    if u+1 <= Z-1:
        if [s, t, u+1] not in data:
            data.append([s, t, u+1])
            hq.heappush(pri, [-A[s]-B[t]-C[u+1],s,t,u+1])
    print(hq.heappop(pri)[0] * -1)

Buggy python submission (verdict: Time Limit Exceeded):
X, Y, Z, K = map(int, input().split())
A = [int(i) for i in input().split()]
B = [int(i) for i in input().split()]
C = [int(i) for i in input().split()]

data_AB = []
for i in range(X):
    for j in range(Y):
        data_AB.append(A[i]+B[j])
data_AB.sort()
data_AB.reverse()
data_AB_K = []
ab = min([K, X*Y])
for i in range(ab):
    data_AB_K.append(data_AB[i])

data_KC = []
C.sort()
C.reverse()
for i in range(ab):
    for j in range(Z):
        data_KC.append(data_AB_K[i] + C[j])
data_KC.sort()
data_KC.reverse()
for i in range(K):
    print(data_KC[i])

Fixed submission:
import heapq as hq

X, Y, Z, K = map(int, input().split())
A = [int(i) for i in input().split()]
B = [int(i) for i in input().split()]
C = [int(i) for i in input().split()]

pri = []
data = []
hq.heapify(pri)

A.sort()
B.sort()
C.sort()
A.reverse()
B.reverse()
C.reverse()

hq.heappush(pri, [-A[0]-B[0]-C[0],0,0,0])
data.append([0,0,0])

for i in range(K):
    s = pri[0][1]
    t = pri[0][2]
    u = pri[0][3]
    if s+1 <= X-1:
        if [s + 1, t, u] not in data:
            data.append([s+1, t, u])
            hq.heappush(pri, [-A[s+1]-B[t]-C[u],s+1,t,u])
    if t+1 <= Y-1:
        if [s, t+1, u] not in data:
            data.append([s, t+1, u])
            hq.heappush(pri, [-A[s]-B[t+1]-C[u],s,t+1,u])
    if u+1 <= Z-1:
        if [s, t, u+1] not in data:
            data.append([s, t, u+1])
            hq.heappush(pri, [-A[s]-B[t]-C[u+1],s,t,u+1])
    print(hq.heappop(pri)[0] * -1)