Go: package main

import (
	"bufio"
	"os"
	"strings"
	"strconv"
	"fmt"
)

var points [5][5][4]bool

var scanner = bufio.NewScanner(os.Stdin)

func main() {
	for i := 0; i < 9; i++ {
		y := i/2
		if i%2 == 0 {
			scanner.Scan()
			info := strings.Split(scanner.Text(), "")
			for k := range info {
				e, _ := strconv.Atoi(info[k])
				if e != 0 {
					points[y][k][1], points[y][k+1][3] = true, true
				}
			}
		} else {
			scanner.Scan()
			info := strings.Split(scanner.Text(), "")
			for k := range info {
				e, _ := strconv.Atoi(info[k])
				if e != 0 {
					points[y][k][2], points[y+1][k][0] = true, true
				}
			}
		}
	}
	x := 1
	y := 0
	dir := 1
	dx := []int{0, 1, 0, -1}
	dy := []int{-1, 0, 1, 0}
	ds := "URDL"
	fmt.Printf("%s", string(ds[dir]))
	for !(x == 0 && y == 0) {
		if points[y][x][(dir+3)%4] {
			dir = (dir+3)%4
		} else if points[y][x][dir] {

		} else if points[y][x][(dir+1)%4] {
			dir = (dir+1)%4
		} else {
			dir = (dir+2)%4
		}
		x += dx[dir]
		y += dy[dir]
		fmt.Printf("%s", string(ds[dir]))
	}
	fmt.Println()
}

C++: #include<string> 
#include<vector>
#include<iostream>
using namespace std;
string vec="RULD";
bool map[20][20][4];
vector< string > maphor,mapver;
int xsize,ysize;
void init(){
	for(int i=0;i<xsize;i++){
		for(int j=0;j<ysize;j++){
			for(int k=0;k<4;k++){
				map[i][j][k]=0;
			}
		}
	}
}
void setmap(){
	for(int i=0;i<xsize;i++){
		for(int j=0;j<ysize;j++){
			if(-1<i&&i<ysize&&-1<j&&j<xsize){
				if(maphor[i][j]=='1'){
					map[i][j][0]=1;
				}
			}
			if(-1<i&&i<ysize&&-1<j-1&&j-1<xsize){
				if(maphor[i][j-1]=='1'){
					map[i][j][2]=1;
				}
			}
			if(-1<i&&i<ysize-1&&-1<j&&j<xsize){
				if(mapver[i][j]=='1'){
					map[i][j][3]=1;
				}
			}
			if(-1<i-1&&i-1<ysize-1&&-1<j&&j<xsize){
				if(mapver[i-1][j]=='1'){
					map[i][j][1]=1;
				}
			}
		}
	}
}

void solve(){
	int x=0,y=0;
	int v=0;
	int loop[4]={1,0,3,2};
	int vx[4]={1,0,-1,0};
	int vy[4]={0,-1,0,1};
	while(1){
		//cout<<x<<" "<<y<<endl;
		for(int i=0;i<4;i++){
			//cout<<vec[(v+loop[i])%4];
			if(x==0&&y==0&&(v+loop[i])%4!=0){
				return;
			}
			if(map[y][x][(v+loop[i])%4]==1){
				v+=loop[i];
				v=v%4;
				x+=vx[v];
				y+=vy[v];
				//cout<<endl;
				cout<<vec[v];
				break;
			}
		}
	}
}

int main(){
	string tmp;
	for(int i=0;cin.eof()!=true;i++){
		cin>>tmp;
		if(i%2==0){
			maphor.push_back(tmp);
		}else{
			mapver.push_back(tmp);
		}
	}
	xsize=maphor[0].size()+1;
	ysize=mapver.size()+1;
	init();setmap();
	
	/*
	for(int i=0;i<xsize;i++){
		for(int j=0;j<ysize;j++){
			for(int k=0;k<4;k++){
				cout<<map[i][j][k];
			}
			cout<<" ";
		}
		cout<<endl;
	}*/
	solve();
	cout<<endl;
	
	return 0;
	
}

C++: #include <iostream>
#include <vector>

using namespace std;

int can[10][10][4];

// RDLU
int dx[] = {1,0,-1,0};
int dy[] = {0,1,0,-1};

string answer;
int dfs(int y,int x,int py,int px,int d){

	if( py != -1 ){
		if( y == py ){
			if( x - px > 0 ) answer += "R"; else answer += "L";
		}else{
			if( y - py > 0 ) answer += "D"; else answer += "U";
		}
	}
	if( py != -1 && x == 0 && y == 0 ) return 0;
	//cout << y << " " << x << " " << can[y][x][0] << " " << can[y][x][1] << " " << can[y][x][2] << " " << can[y][x][3] << " " << endl;
	
	for(int i = 0 ; i < 4 ; i++){
		if( can[y][x][(i+d)%4]  ){
			int tx = x + dx[(i+d)%4];
			int ty = y + dy[(i+d)%4];
			if( tx == px && ty == py ) continue;
			can[y][x][(i+d)%4] = 0;
			dfs(ty,tx,y,x,(i+d)%4);
			return 0;
		}
	}
	for(int i = 0 ; i < 4 ; i++){
		if( can[y][x][(i+d)%4]  ){
			can[y][x][(i+d)%4] = 0;
			int tx = x + dx[(i+d)%4];
			int ty = y + dy[(i+d)%4];
			//if( tx == px && ty == py ) continue;
			dfs(ty,tx,y,x,(i+d)%4);
			return 0;
		}
	}
}// RDLU
int main(){

	for(int i = 0 ; i < 9 ; i++){
		if( i % 2 ){
			for(int j = 0 ; j < 5 ; j++){
				char c;
				cin >> c;
				if( c == '1' ){
					can[i/2][j][1] = 1;
					can[i/2+1][j][3] = 1;
				}
			}
		}else{
			for(int j = 0 ; j < 4 ; j++){
				char c;
				cin >> c;
				if( c == '1' ){
					can[i/2][j][0] = 1; 
					can[i/2][j+1][2] = 1;
				}
			}
		}
	}
	dfs(0,0,-1,-1,0);
	cout << answer << endl;
	char c;
	if( (cin >> c) ) while(1){}
}

C++: #include <iostream>

using namespace std;

enum Direction {R, L, U, D};

bool input(char b[][5])
{
	char dummy;
	for (int i=0; i<9; i++) {
		for (int j=0; j<5; j++) {
			if ((i&1)==0 && j==4) continue;
			if ( !(cin >> b[i][j]) ) return false;
		}
		//cin >> dummy;
	}
	return true;
}

int main()
{
	char board[9][5];
	input(board);
	
	pair<int, int> curr_pos = (board[1][0] == '1') ? pair<int,int>(1,0) : pair<int,int>(0,0);
	enum Direction curr_dir = (board[1][0] == '1') ? D : R;
	cout << curr_dir;
	
	do {
		switch (curr_dir) {
		case R:
			// priority : U > R > D
			if ( curr_pos.first > 0 && board[curr_pos.first-1][curr_pos.second+1] == '1' ) {
				curr_dir = U; cout << "U"; curr_pos.first--; curr_pos.second++;
			} else if ( curr_pos.second < 3 && board[curr_pos.first][curr_pos.second+1] == '1' ){
				curr_dir = R; cout << "R"; curr_pos.second++;
			} else {
				curr_dir = D; cout << "D"; curr_pos.first++; curr_pos.second++;
			} 
			break;
		case L:
			// priority : D > L > U
			if ( curr_pos.first < 8 && board[curr_pos.first+1][curr_pos.second] == '1' ) {
				curr_dir = D; cout << "D"; curr_pos.first++;
			} else if ( curr_pos.second > 0 && board[curr_pos.first][curr_pos.second-1] == '1' ) {
				curr_dir = L; cout << "L"; curr_pos.second--;
			} else {
				curr_dir = U; cout << "U"; curr_pos.first--;
			}
			break;
		case U:
			// priority : L > U > R
			if ( curr_pos.second > 0 && board[curr_pos.first-1][curr_pos.second-1] == '1' ) {
				curr_dir = L; cout << "L"; curr_pos.first--; curr_pos.second--;
			} else if ( curr_pos.first > 2 && board[curr_pos.first-2][curr_pos.second] == '1' ) {
				curr_dir = U; cout << "U"; curr_pos.first-=2;
			} else {
				curr_dir = R; cout << "R"; curr_pos.first--;
			}
			break;
		case D:
			// priority : R > D > L
			if ( board[curr_pos.first+1][curr_pos.second] == '1' ) {
				curr_dir = R; cout << "R"; curr_pos.first++;
			} else if ( curr_pos.first < 6 && board[curr_pos.first+2][curr_pos.second] == '1' ) {
				curr_dir = D; cout << "D"; curr_pos.first+=2;
			} else {
				curr_dir = L; cout << "L"; curr_pos.first++; curr_pos.second--;
			}
			break;
		}
	} while ( curr_pos.first != 0 || curr_pos.second != 0 );
	
	cout << endl;
	
	return 0;
}