from bisect import bisect_left, bisect_right

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

A.sort()
B.sort()

hi = P
lo = 0

while hi - lo > 1:
    md = (hi + lo) >> 1
    tmp = 0
    for i, a in enumerate(A):
        if a < md:
            tmp += bisect_left(B, md - a)
            tmp += N - bisect_left(B, P - a)
        else:
            tmp += bisect_left(B, P + md - a) - bisect_left(B, P - a)
    if tmp < K:
        lo = md
    else:
        hi = md

print(lo)