Buggy python submission (verdict: Time Limit Exceeded):
import numpy as np
import sys

X, Y, Z, K = map(int, input().split())
a = np.array(list(map(int, sys.stdin.readline().split())), dtype='int64')
b = np.array(list(map(int, sys.stdin.readline().split())), dtype='int64')
c = np.array(list(map(int, sys.stdin.readline().split())), dtype='int64')

amax = a.max()
bmax = b.max()
cmax = c.max()

a = amax - a
a.sort()
b = bmax - b
b.sort()
c = cmax - c
c.sort()


def func(o, p):
    min_ = 0
    max_ = o[-1] + p[-1]
    v = (min_ + max_) // 2
    while True:
        mat = np.searchsorted(o, v - p, side='right')
        sum_ = mat.sum()
        if sum_ > K:
            max_ = v - 1
            v = (v + min_) // 2
        elif sum_ == K:
            return v
        else:
            min_ = v + 1
            v = (v + max_ + 1) // 2


if X * Y > K:
    u = func(a, b)
    matr = np.searchsorted(a, u - b, side='right')
    d = np.array([],dtype='int64')
    for i in range(Y):
        d = np.append(d, a[:matr[i]] + b[i])
    d.sort()
else:
    d = (a + b.reshape([len(b), 1])).flatten()
    d.sort()

u = func(d, c)
matr = np.searchsorted(d, u - c, side='right')
e = np.array([],dtype='int64')
for i in range(Z):
    e = np.append(e, d[:matr[i]] + c[i])
e.sort()

t = amax + bmax + cmax
for ec in e:
    print(t - ec)

Fixed submission:
import numpy as np
import sys

X, Y, Z, K = map(int, input().split())
a = np.array(list(map(int, sys.stdin.readline().split())), dtype='int64')
b = np.array(list(map(int, sys.stdin.readline().split())), dtype='int64')
c = np.array(list(map(int, sys.stdin.readline().split())), dtype='int64')

d = (a + b.reshape([len(b), 1])).flatten()
d.sort()
e = (d[-K:] + c.reshape([len(c), 1])).flatten()
e.sort()

for ec in e[-K:][::-1]:
    print(ec)

Buggy python submission (verdict: Time Limit Exceeded):
import numpy as np

X, Y, Z, K = map(int, input().split())
a = np.array(list(map(int, input().split())), dtype='int64')
b = np.array(list(map(int, input().split())), dtype='int64')
c = np.array(list(map(int, input().split())), dtype='int64')

amax = a.max()
bmax = b.max()
cmax = c.max()

a = amax - a
a.sort()
b = bmax - b
b.sort()
c = cmax - c
c.sort()


def func(o, p):
    min_ = 0
    max_ = o[-1] + p[-1]
    v = (min_ + max_) // 2
    while True:
        mat = np.searchsorted(o, v - p, side='right')
        sum_ = mat.sum()
        if sum_ > K:
            max_ = v - 1
            v = (v + min_) // 2
        elif sum_ == K:
            return v
        else:
            min_ = v + 1
            v = (v + max_ + 1) // 2


if X * Y > K:
    u = func(a, b)
    matr = np.searchsorted(a, u - b, side='right')
    d = np.array([],dtype='int64')
    for i in range(Y):
        d = np.append(d, a[:matr[i]] + b[i])
    d.sort()
else:
    d = (a + b.reshape([len(b), 1])).flatten()
    d.sort()

u = func(d, c)
matr = np.searchsorted(d, u - c, side='right')
e = np.array([],dtype='int64')
for i in range(Z):
    e = np.append(e, d[:matr[i]] + c[i])
e.sort()

t = amax + bmax + cmax
for ec in e:
    print(t - ec)

Fixed submission:
import numpy as np
import sys

X, Y, Z, K = map(int, input().split())
a = np.array(list(map(int, sys.stdin.readline().split())), dtype='int64')
b = np.array(list(map(int, sys.stdin.readline().split())), dtype='int64')
c = np.array(list(map(int, sys.stdin.readline().split())), dtype='int64')

d = (a + b.reshape([len(b), 1])).flatten()
d.sort()
e = (d[-K:] + c.reshape([len(c), 1])).flatten()
e.sort()

for ec in e[-K:][::-1]:
    print(ec)