func_code_string: #include <bits/stdc++.h>   using namespace std;   template <typename T, typename U>   std::istream& operator>>(std::istream& i, pair<T, U>& p) {     i >> p.first >> p.second;     return i;   }   template <typename T>   std::istream& operator>>(std::istream& i, vector<T>& t) {     for (auto& v : t) {       i >> v;     }     return i;   }   template <typename T, typename U>   std::ostream& operator<<(std::ostream& o, const pair<T, U>& p) {     o << p.first <<     << p.second;     return o;   }   template <typename T>   std::ostream& operator<<(std::ostream& o, const vector<T>& t) {     if (t.empty()) o <<   n ;     for (size_t i = 0; i < t.size(); ++i) {       o << t[i] <<    n [i == t.size() - 1];     }     return o;   }   template <typename T>   using minheap = priority_queue<T, vector<T>, greater<T>>;   template <typename T>   using maxheap = priority_queue<T, vector<T>, less<T>>;   template <typename T>   bool in(T a, T b, T c) {     return a <= b && b < c;   }   unsigned int logceil(long long first) {     return first ? 8 * sizeof(long long) - __builtin_clzll(first) : 0;   }   namespace std {   template <typename T, typename U>   struct hash<pair<T, U>> {     hash<T> t;     hash<U> u;     size_t operator()(const pair<T, U>& p) const {       return t(p.first) ^ (u(p.second) << 7);     }   };   }  // namespace std   template <typename T, typename F>   T bsh(T l, T h, const F& f) {     T r = -1, m;     while (l <= h) {       m = (l + h) / 2;       if (f(m)) {         l = m + 1;         r = m;       } else {         h = m - 1;       }     }     return r;   }   template <typename F>   double bshd(double l, double h, const F& f, double p = 1e-9) {     unsigned int r = 3 + (unsigned int)log2((h - l) / p);     while (r--) {       double m = (l + h) / 2;       if (f(m)) {         l = m;       } else {         h = m;       }     }     return (l + h) / 2;   }   template <typename T, typename F>   T bsl(T l, T h, const F& f) {     T r = -1, m;     while (l <= h) {       m = (l + h) / 2;       if (f(m)) {         h = m - 1;         r = m;       } else {         l = m + 1;       }     }     return r;   }   template <typename F>   double bsld(double l, double h, const F& f, double p = 1e-9) {     unsigned int r = 3 + (unsigned int)log2((h - l) / p);     while (r--) {       double m = (l + h) / 2;       if (f(m)) {         h = m;       } else {         l = m;       }     }     return (l + h) / 2;   }   template <typename T>   T gcd(T a, T b) {     if (a < b) swap(a, b);     return b ? gcd(b, a % b) : a;   }   template <typename T>   class vector2 : public vector<vector<T>> {    public:     vector2() {}     vector2(size_t a, size_t b, T t = T())         : vector<vector<T>>(a, vector<T>(b, t)) {}   };   template <typename T>   class vector3 : public vector<vector2<T>> {    public:     vector3() {}     vector3(size_t a, size_t b, size_t c, T t = T())         : vector<vector2<T>>(a, vector2<T>(b, c, t)) {}   };   template <typename T>   class vector4 : public vector<vector3<T>> {    public:     vector4() {}     vector4(size_t a, size_t b, size_t c, size_t d, T t = T())         : vector<vector3<T>>(a, vector3<T>(b, c, d, t)) {}   };   template <typename T>   class vector5 : public vector<vector4<T>> {    public:     vector5() {}     vector5(size_t a, size_t b, size_t c, size_t d, size_t e, T t = T())         : vector<vector4<T>>(a, vector4<T>(b, c, d, e, t)) {}   };   class ENeatness {    public:     int N, A, B, X, Y;     string Sol;     vector<vector<bool>> L, V;     vector<int> LOX, HIX, LOY, HIY;     constexpr char op(char c) {       switch (c) {         case  L :           return  R ;         case  R :           return  L ;         case  D :           return  U ;         case  U :           return  D ;         case  1 :           return  2 ;         case  2 :           return  1 ;         default:           return  x ;       }     }     void goUp() {       if (A == 0) return;       while (B > 0 && L[A][B - 1]) {         add( L );         --B;       }       while (B < N - 1 && !L[A - 1][B] && L[A][B + 1]) {         add( R );         ++B;       }       if (L[A - 1][B]) {         --A;         add( U );         goUp();       }     }     void goDown() {       if (A == N - 1) return;       while (B > 0 && L[A][B - 1]) {         add( L );         --B;       }       while (B < N - 1 && !L[A + 1][B] && L[A][B + 1]) {         add( R );         ++B;       }       if (L[A + 1][B]) {         ++A;         add( D );         goDown();       }     }     void turnOffAndDown() {       if (A == X) return;       int b = -1;       for (int i = 0; i < N; ++i) {         if (L[A][i] && L[A + 1][i]) {           b = i;         }       }       while (B > 0 && L[A][B - 1]) {         add( L );         --B;       }       while (B < N - 1 && L[A][B + 1]) {         if (B != b) {           add( 2 );           L[A][B] = false;         }         add( R );         ++B;       }       if (B != b) {         add( 2 );         L[A][B] = false;       }       while (B != b) {         add( L );         --B;       }       add( 2 );       L[A][B] = false;       add( D );       ++A;       turnOffAndDown();     }     void turnOffAndUp() {       int b = Y;       if (A != X) {         for (int i = 0; i < N; ++i) {           if (L[A][i] && L[A - 1][i]) {             b = i;           }         }       }       while (B > 0 && L[A][B - 1]) {         add( L );         --B;       }       while (B < N - 1 && L[A][B + 1]) {         if (B != b) {           add( 2 );           L[A][B] = false;         }         add( R );         ++B;       }       if (B != b) {         add( 2 );         L[A][B] = false;       }       while (B != b) {         add( L );         --B;       }       add( 2 );       L[A][B] = false;       if (A == X) return;       add( U );       --A;       turnOffAndUp();     }     void add(char c) {       if (!Sol.empty() && Sol.back() == op(c))         Sol.pop_back();       else         Sol.push_back(c);     }     void bfs(int i, int j) {       if (V[i][j]) return;       V[i][j] = true;       if (!L[i][j]) {         add( 1 );         L[i][j] = true;         LOX[i] = min(LOX[i], j);         HIX[i] = max(HIX[i], j);         LOY[j] = min(LOY[j], i);         HIY[j] = max(HIY[j], i);       }       if (LOX[i] < j) {         add( L );         bfs(i, j - 1);         add( R );       }       if (HIX[i] > j) {         add( R );         bfs(i, j + 1);         add( L );       }       if (LOY[j] < i) {         add( U );         bfs(i - 1, j);         add( D );       }       if (HIY[j] > i) {         add( D );         bfs(i + 1, j);         add( U );       }     }     void solve(istream& cin, ostream& cout) {       cin >> N >> A >> B;       L = vector2<bool>(N, N);       V = vector2<bool>(N, N, false);       for (auto& l : L) {         for (int i = 0; i < N; ++i) {           bool c;           cin >> c;           l[i] = c;         }       }       LOX.assign(N, N);       LOY.assign(N, N);       HIX.assign(N, -1);       HIY.assign(N, -1);       for (int i = 0; i < N; ++i) {         for (int j = 0; j < N; ++j) {           if (L[i][j]) {             LOX[i] = min(LOX[i], j);             HIX[i] = max(HIX[i], j);             LOY[j] = min(LOY[j], i);             HIY[j] = max(HIY[j], i);           }         }       }       --A;       --B;       X = A;       Y = B;       bfs(A, B);       goUp();       turnOffAndDown();       goDown();       turnOffAndUp();       for (int i = 0; i < N; ++i) {         for (int j = 0; j < N; ++j) {           if (L[i][j]) {             cout <<  NO n ;             return;           }         }       }       cout <<  YES n  << Sol <<   n ;     }   };   int main() {     ios_base::sync_with_stdio(false);     cin.tie(nullptr);     cout.tie(nullptr);     ENeatness solver;     std::istream& in(std::cin);     std::ostream& out(std::cout);     solver.solve(in, out);     return 0;   }   