func_code_string: #include <bits/stdc++.h>   using namespace std;   const int N = 15;   const int M = 11005;   const int mo1 = 317503;   const int mo2 = 1000000007;   const int BAS = 2333;   const int P = 3000005;   int n, m, k, Hash[N], bel[N], tot, matching[M][N][2], temp_matching[N][2],       bin[N];   long long ans, jc[N];   vector<int> e[N];   int ls[mo1], nx[P], key[P], tot_hash;   bool vis[N], trans[N][N][N][N], f[5005][N];   void add_hash(int *Hash) {     int h1 = 0, h2 = 0;     for (int i = 1; i <= n; i++) {       h1 = ((long long)h1 * BAS + Hash[i]) % mo1;       h2 = ((long long)h2 * BAS + Hash[i]) % mo2;     }     for (int i = ls[h1]; i; i = nx[i])       if (key[i] == h2) return;     key[++tot_hash] = h2;     nx[tot_hash] = ls[h1];     ls[h1] = tot_hash;   }   bool find_hash(int *Hash) {     int h1 = 0, h2 = 0;     for (int i = 1; i <= n; i++) {       h1 = ((long long)h1 * BAS + Hash[i]) % mo1;       h2 = ((long long)h2 * BAS + Hash[i]) % mo2;     }     for (int i = ls[h1]; i; i = nx[i])       if (key[i] == h2) return 1;     return 0;   }   void dfs_matching(int x) {     if (x > n / 2) {       tot++;       for (int i = 1; i <= n / 2; i++) {         matching[tot][i][0] = temp_matching[i][0];         matching[tot][i][1] = temp_matching[i][1];       }       return;     }     int u;     for (int i = 1; i <= n; i++)       if (!vis[i]) {         u = i;         vis[i] = 1;         break;       }     temp_matching[x][0] = u;     for (int j = u + 1; j <= n; j++)       if (!vis[j]) {         temp_matching[x][1] = j;         vis[j] = 1;         dfs_matching(x + 1);         vis[j] = 0;       }     vis[u] = 0;   }   void dfs_half_divide(int x, int y, int id) {     if (x > n / 2) {       for (int i = 1; i <= n / 2; i++)         Hash[matching[id][i][0]] = Hash[matching[id][i][1]] = bel[i];       add_hash(Hash);       return;     }     for (int i = 1; i <= y; i++) {       bel[x] = i;       dfs_half_divide(x + 1, y, id);     }     bel[x] = y + 1;     dfs_half_divide(x + 1, y + 1, id);   }   void dfs_divide(int x, int y) {     if (x > n) {       for (int i = 1; i <= n; i++) Hash[i] = bel[i];       if (find_hash(Hash) && y <= k) ans += jc[k] / jc[k - y];       return;     }     for (int i = 1; i <= y; i++) {       bel[x] = i;       dfs_divide(x + 1, y);     }     bel[x] = y + 1;     dfs_divide(x + 1, y + 1);   }   void pre_matching() {     bin[0] = 1;     for (int i = 1; i <= n; i++) bin[i] = bin[i - 1] * 2;     for (int u = 1; u <= n; u++)       for (int v = 1; v <= n; v++)         for (int i : e[u])           for (int j : e[v]) trans[u][v][i][j] = 1;     for (int i = 1; i <= tot; i++) {       memset(f, 0, sizeof(f));       for (int j = 1; j <= n / 2; j++) f[bin[j - 1]][j] = 1;       for (int j = 1; j < bin[n / 2] - 1; j++)         for (int k = 1; k <= n / 2; k++) {           int u = matching[i][k][0], v = matching[i][k][1];           if (f[j][k]) {             for (int l = 1; l <= n / 2; l++)               if (!(j & bin[l - 1])) {                 int p = matching[i][l][0], q = matching[i][l][1];                 f[j + bin[l - 1]][l] |= trans[u][v][p][q] | trans[u][v][q][p];               }           }         }       bool tag = 0;       for (int j = 1; j <= n / 2; j++) {         int u = matching[i][j][0], v = matching[i][j][1];         tag |= f[bin[n / 2] - 1][j] & trans[u][v][v][u];       }       if (tag) dfs_half_divide(1, 0, i);     }   }   int main() {     scanf( %d%d%d , &n, &m, &k);     for (int i = 1; i <= m; i++) {       int x, y;       scanf( %d%d , &x, &y);       e[x].push_back(y);       e[y].push_back(x);     }     jc[0] = 1;     for (int i = 1; i <= k; i++) jc[i] = jc[i - 1] * i;     dfs_matching(1);     pre_matching();     dfs_divide(1, 0);     printf( %lld n , ans);     return 0;   }   