func_code_string: #include <bits/stdc++.h>   using namespace std;   struct node {     int hx, hy;     int tx, ty;     int dep;     long dir;     int zt[15];   };   queue<node> q;   int n, m, len;   int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};   bool v[15][15][262144];   char c[30][30];   bool init(int a, int b) {     if (a < 0 || a >= n || b < 0 || b >= m) return 0;     return 1;   }   int update(int d, int nd) {     d = d | (nd << ((len - 1) * 2));     d >>= 2;     return d;   }   void out(int d) {     for (int i = 1; i < len; i++) {       int t = d % 4;       if (t == 0) cout <<  w ;       if (t == 1) cout <<  d ;       if (t == 2) cout <<  s ;       if (t == 3) cout <<  a ;       d /= 4;     }   }   void zut(int x) {     for (int i = 1; i <= m; i++) {       cout << x % 2;       x /= 2;     }   }   int ax, ay;   node fst;   int main() {     cin >> n >> m;     int fhx, fhy, ftx, fty;     for (int i = 0; i < n; i++)       for (int j = 0; j < m; j++) {         cin >> c[i][j];         if (c[i][j] >=  1  && c[i][j] <=  9 ) len = max(len, c[i][j] -  0 );         if (c[i][j] ==  1 ) {           fhx = i;           fhy = j;         }         if (c[i][j] == len +  0 ) {           ftx = i;           fty = j;         }         if (c[i][j] ==  @ ) {           ax = i;           ay = j;         }       }     int fdir = 0;     for (int i = 0; i < n; i++)       for (int j = 0; j < m; j++)         if (c[i][j] >=  1  && c[i][j] <=  9 ) {           for (int k = 0; k < 4; k++) {             int nx = i + dx[k], ny = j + dy[k];             if (init(nx, ny) && c[nx][ny] == c[i][j] - 1) {               int nk = k;               fdir = fdir | (nk << ((len - (c[i][j] -  0 )) * 2));               break;             }           }           fst.zt[i] |= (1 << j);         }     fst.dir = fdir, fst.hx = fhx, fst.hy = fhy, fst.tx = ftx, fst.ty = fty,     fst.dep = 0;     q.push(fst);     while (!q.empty()) {       node f = q.front();       q.pop();       if (f.hx == ax && f.hy == ay) {         cout << f.dep;         return 0;       } else {         for (int i = 0; i < 4; i++) {           int nx = f.hx + dx[i], ny = f.hy + dy[i];           if (!init(nx, ny)) continue;           if (c[nx][ny] ==  # ) continue;           if (f.zt[nx] & (1 << ny) && !(nx == f.tx && ny == f.ty)) continue;           node nf = f;           nf.hx = nx;           nf.hy = ny;           nf.tx = dx[f.dir & (3)] + f.tx;           nf.ty = dy[f.dir & (3)] + f.ty;           nf.zt[f.tx] ^= (1 << f.ty);           nf.zt[nx] |= (1 << ny);           nf.dir = update(f.dir, i);           nf.dep++;           if (v[nx][ny][nf.dir]) continue;           v[nx][ny][nf.dir] = 1;           q.push(nf);         }       }     }     cout << -1;     return 0;   }   