{"trustable":false,"sections":[{"title":"","value":{"format":"MD","content":"给你四个数列A,B,C,D。从每个数列中各取出一个数,问有多少种方案使得4个数的和为0。\n当一个数列中有多个相同的数字的时候,把它们当做不同的数对待。\n"}},{"title":"Input","value":{"format":"MD","content":"第一行:n(代表数列中数字的个数) **(1≤n≤4000)**\n第二行:依次输入A,B,C,D(数字不超过2的28次方)"}},{"title":"Output","value":{"format":"MD","content":"输出不同组合的个数。"}},{"title":"Sample Input","value":{"format":"MD","content":"6\n-45 22 42 -16\n-41 -27 56 30\n-36 53 -37 77\n-36 30 -75 -46\n26 -38 -10 62\n-32 -54 -6 45"}},{"title":"Sample Output","value":{"format":"MD","content":"5"}},{"title":"Hint","value":{"format":"MD","content":"样例解释: (-45, -27, 42, 30), (26, 30, -10, -46), (-32, 22, 56, -46),(-32, 30, -75, 77), (-32, -54, 56, 30)."}}]}