#include <iostream>
#include <vector>
#include <queue>
#include <unordered_set>

struct Vosminashka{
    std::vector<std::vector<int> > table;
    std::string way;
    Vosminashka();
    int operator[](int i) const;
    long long getHash() const;
    void down();
    void up();
    void left();
    void right();
    void addStep(char c);
    bool endOfGame() const;
};

Vosminashka::Vosminashka() {
    table = std::vector<std::vector<int> >(3,std::vector<int>(3));
}

int Vosminashka::operator[](int i) const{
    if(i < 9){
        return table[i/3][i%3];
    } else {
        return -1;
    }
}

long long Vosminashka::getHash() const{
    long long result = 0;
    long long deg = 10;
    for(int i = 0; i < 9; ++i){
        result += this->operator[](i)*deg;
        deg*=10;
    }
    return result;
}

void Vosminashka::up() {
    for(int i = 1; i < 3; ++i){
        for(int j = 0; j < 3; ++j){
            if(table[i][j] == 0){
                std::swap(table[i][j],table[i-1][j]);
                return;
            }
        }
    }
}

void Vosminashka::down() {
    for(int i = 0; i < 2; ++i){
        for(int j = 0; j < 3; ++j){
            if(table[i][j] == 0){
                std::swap(table[i][j],table[i+1][j]);
                return;
            }
        }
    }
}

void Vosminashka::left() {
    for(int i = 0; i < 3; ++i){
        for(int j = 1; j < 3; ++j){
            if(table[i][j] == 0){
                std::swap(table[i][j-1],table[i][j]);
                return;
            }
        }
    }
}

void Vosminashka::right() {
    for(int i = 0; i < 3; ++i){
        for(int j = 0; j < 2; ++j){
            if(table[i][j] == 0){
                std::swap(table[i][j],table[i][j+1]);
                return;
            }
        }
    }
}

void Vosminashka::addStep(char c) {
    way+=c;
}

bool Vosminashka::endOfGame() const{
    if(table[2][2] != 0)
        return false;
    for(int i = 1; i < 8; ++i){
        if(this->operator[](i) < this->operator[](i-1)) {
            return false;
        }
    }
    return true;
}

bool possibleSolution(Vosminashka const &game){
    int counter = 0;
    for(int i = 0; i < 8; ++i){
        for(int j = i + 1; j < 9; ++j){
            if(game[i] > game[j] && game[i] != 0 && game[j] != 0)
                ++counter;
        }
    }

    return counter%2 == 0;

}

Vosminashka win(Vosminashka game){
    if(!possibleSolution(game)) {
        game.addStep('0');
        return game;
    }

    std::deque<Vosminashka> bfsDeque;
    std::unordered_set<long long> used;
    used.insert(game.getHash());
    bfsDeque.push_back(game);
    while(!bfsDeque.empty()){
        Vosminashka curGame = bfsDeque.front();
        if(curGame.endOfGame()) {
            return curGame;
        }
        bfsDeque.pop_front();

        Vosminashka newGame = curGame;
        newGame.down();
        if(used.find(newGame.getHash()) == used.end()){
            newGame.addStep('D');
            bfsDeque.push_back(newGame);
            used.insert(newGame.getHash());
        }

        newGame = curGame;
        newGame.up();
        if(used.find(newGame.getHash()) == used.end()){
            newGame.addStep('U');
            bfsDeque.push_back(newGame);
            used.insert(newGame.getHash());
        }

        newGame = curGame;
        newGame.left();
        if(used.find(newGame.getHash()) == used.end()){
            newGame.addStep('L');
            bfsDeque.push_back(newGame);
            used.insert(newGame.getHash());
        }

        newGame = curGame;
        newGame.right();
        if(used.find(newGame.getHash()) == used.end()){
            newGame.addStep('R');
            bfsDeque.push_back(newGame);
            used.insert(newGame.getHash());

        }

    }

    return game;

}


int main() {
    Vosminashka game;
    for(int i = 0; i < 9; ++i){
        std::cin >> game.table[i/3][i%3];
    }
    Vosminashka result = win(game);
    if(result.way == "0") {
        std::cout << "-1";
    } else{
        std::cout << result.way.size() << std::endl;
        std::cout << result.way;
    }

    return 0;

}