func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n, i, res = 0, j, mid, a[6] = {}, b[6] = {};     cin >> n;     for (i = 0; i < n; i++) {       cin >> j;       a[j]++;     }     for (i = 0; i < n; i++) {       cin >> j;       b[j]++;     }     for (i = 1; i < 6; i++) {       mid = a[i] + b[i];       if (mid % 2) {         cout << -1 << endl;         return 0;       }       res += abs(a[i] - mid / 2);     }     cout << res / 2 << endl;     return 0;   }   