import numpy as np
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

n = int(input())
a = np.flipud(np.array(readline().split(),np.int32))
b = np.flipud(np.array(readline().split(),np.int32))
d = np.array(readline().split(),np.int32)
d.sort()

dp = np.zeros((3003, 3003), dtype=int)

for i in range(n+1):
    for j in range(n+1):
        #print(i, j)
        if i > 0:
            dp[i][j] = max(dp[i][j], dp[i-1][j])

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

        if dp[i][j] == n:
            continue
        if i == n and j == n:
            continue
        if a[i] + b[j] >= d[dp[i][j]]:
            dp[i][j] += 1

print(dp[n][n])