func_code_string: #include <bits/stdc++.h>   using namespace std;   #pragma comment(linker,  /stack:200000000 )   #pragma GCC optimize( Ofast )   #pragma GCC target(         sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native )   #pragma GCC optimize( -ffloat-store )   const long long INF = 9e18;   const long long N = 998244353;   const double eps = 1e-9;   const auto start_time = std::chrono::high_resolution_clock::now();   void zark() {}   void solve() {     long long n, k;     cin >> n >> k;     vector<long long> a(n), b(n);     for (long long i = (0); i < (n); i++) cin >> a[i];     for (long long i = (0); i < (n); i++) cin >> b[i];     sort((a).begin(), (a).end());     sort((b).begin(), (b).end());     long long s = 0;     long long i = 0, j = n - 1, cnt = 0;     while (cnt < k && i < n && j >= 0) {       if (a[i] < b[j])         s += b[j], cnt++, j--, i++;       else         break;     }     for (long long ii = i; ii < n; ii++) s += a[ii];     cout << s <<   n ;   }   int32_t main() {     ios::sync_with_stdio(0);     cin.tie(0);     cout.tie(0);     ;     long long t;     cin >> t;     while (t--) solve();     zark();     return 0;   }   