解法：

桶

#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
#define endl '\n'int main() {ios::sync_with_stdio(false);cin.tie(0); cout.tie(0);vector<int> tong(1001);int t = 4;int k, pai;long long suma = 0, sum = 0;while (t--) {cin >> k;while (k--) {cin >> pai;tong[pai]++;}}for (int i = 1; i < 1001; i++) {if (!tong[i]) continue;suma++;sum += tong[i];}cout << suma * 4 - sum << endl;return 0;
}