#include <bits/stdc++.h>   char T[1 << 21];   int n, m, ar[21][21];   int U[21], V[21], P[21], way[21], minv[21];   int hungarian(int n, int m, int ar[21][21]) {     memset(way, 0, sizeof(way)), memset(U, 0, sizeof(U)), memset(V, 0, sizeof(V)),         memset(P, 0, sizeof(P));     int i, j, i0, i1, j0, j1, x, y, cur, delta, used, lim = (1 << (m + 1)) - 1;     for (i = 1; i <= n; i++) {       used = 0;       P[0] = i, j0 = 0;       for (j = 0; j <= m; j++) minv[j] = (1 << 27);       do {         used |= (1 << j0);         i0 = P[j0], j1 = 0, delta = (1 << 27), x = (used | 1) ^ lim;         while (x) {           y = (-x & x);           j = T[y];           x ^= y;           cur = ar[i0][j] - U[i0] - V[j];           if (cur < minv[j]) {             minv[j] = cur;             way[j] = j0;           }           if (minv[j] < delta) {             delta = minv[j];             j1 = j;           }         }         for (j = 0; j <= m; j++) {           if (used & (1 << j)) {             U[P[j]] += delta;             V[j] -= delta;           } else             minv[j] -= delta;         }         j0 = j1;       } while (P[j0] != 0);       do {         j1 = way[j0];         P[j0] = P[j1];         j0 = j1;       } while (j0 != 0);     }     return -V[0];   }   int fri[21][21], sat[21][21];   int main() {     int i, j, k, x, res, lim, mask;     for (i = 0; i < 21; i++) T[1 << i] = i;     while (scanf( %d , &n) != EOF) {       for (i = 0; i < n; i++) {         for (j = 0; j < n; j++) {           scanf( %d , &fri[i][j]);         }       }       for (i = 0; i < n; i++) {         for (j = 0; j < n; j++) {           scanf( %d , &sat[i][j]);         }       }       res = 0, lim = 1 << n;       for (mask = 0; mask < lim; mask++) {         if (__builtin_popcount(mask) == (n >> 1)) {           for (i = 0; i < n; i++) {             for (j = 0; j < n; j++) {               if (mask & (1 << i))                 ar[i + 1][j + 1] = -fri[i][j];               else                 ar[i + 1][j + 1] = -sat[i][j];             }           }           x = -hungarian(n, n, ar);           if (x > res) res = x;         }       }       printf( %d n , res);     }     return 0;   }   