#!/usr/bin/env pypy3

n = int(input())
a = list(map(int, input().split()))
b = list(map(int, input().split()))
d = list(map(int, input().split()))

d.sort()

dp = [[0 for j in range(n + 1)] for i in range(n + 1)]
dp[0][0] = n + 1
ans = 0
for i in range(n + 1):
    k = n
    for j in range(n + 1):
        if i == 0 and j == 0:
            continue
        while k > 0 and d[k - 1] > a[i] + b[j]:
            k -= 1

        ma = -1
        if i > 0:
            ma = max(ma, dp[i - 1][j] - 1)
        if j > 0:
            ma = max(ma, dp[i][j - 1] - 1)

        dp[i][j] = min(k, ma)
        if dp[i][j] > 0:
            ans = max(ans, i + j)
        else:
            break

print(ans)