N, K, P = map(int, input().split())
A = list(map(int, input().split()))
B = list(map(int, input().split()))
A.sort()
B.sort()
X = [0]*N
for i in range(N):
    l, r = 0, N
    d = N // 2
    if A[i] + B[0] >= P:
        continue
    while r - l > 1:
        if A[i] + B[d] < P:
            l = d
        else:
            r = d
        d = (l + r) // 2
    X[i] = d + 1
L, R = 0, P
D = P // 2
while R - L > 1:
    cnt = 0
    for i in range(N):
        if A[i] + B[0] < D:
            l, r = 0, N
            d = N // 2
            while r - l > 1:
                if A[i] + B[d] < D:
                    l = d
                else:
                    r = d
                d = (l + r) // 2
            cnt += d + 1
        if A[i] + B[0] < D + P:
            l, r = 0, N
            d = N // 2
            while r - l > 1:
                if A[i] + B[d] < D + P:
                    l = d
                else:
                    r = d
                d = (l + r) // 2
            cnt += d + 1 - X[i]
    if cnt < K:
        L = D
    else:
        R = D
    D = (L + R) // 2
print(D)