/*
 * Package: StandardCodeLibrary.Core
 * */
#include <iostream>
#include <fstream>
#include <sstream>
#include <iomanip>
#include <utility>
#include <vector>
#include <list>
#include <string>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <numeric>
#include <bitset>
#include <complex>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <cstdlib>
#include <ctime>
#include <climits>
using namespace std;

#define lp for(;;)
#define repf(i,a,b) for (int i=(a);i<(b);++i)
#define rrepf(i,a,b) for (int i=(a)-1;i>=(b);--i)
#define rep(i,n) repf(i,0,n)
#define rrep(i,n) rrepf(i,n,0)
#define ft(i,a,b) for (int i=(a);i<=(b);++i)
#define fdt(i,a,b) for (int i=(a);i>=(b);--i)
#define for_nonempty_subsets(subset,set) for (int subset=set;subset;subset=(subset-1)&(set))
#define for_in_charset(i,charset) for (cstr i=(charset);*i;i++)
#define whl while
#define rtn return
#define fl(x,y) memset((x),char(y),sizeof(x))
#define clr(x) fl(x,char(0))
#define cpy(x,y) memcpy(x,y,sizeof(x))
#define sf scanf
#define pf printf
#define vec vector
#define pr pair
#define que queue
#define prq priority_queue
#define itr iterator
#define x first
#define y second
#define pb push_back
#define mp make_pair
#define ins insert
#define ers erase
#define lb lower_bound
#define ub upper_bound
#define rnk order_of_key
#define sel find_by_order
#define sz(x) (int((x).size()))
#define all(x) (x).begin(),(x).end()
#define srt(x) sort(all(x))
#define uniq(x) srt(x),(x).erase(unique(all(x)),(x).end())
#define rev(x) reverse(all(x))
#define shf(x) random_shuffle(all(x))
#define nxtp(x) next_permutation(all(x))

#ifndef DEBUG
#define prt(x) (cerr)
#define asrtWA(s) do if(!(s))exit(0);whl(0)
#define asrtTLE(s) do if(!(s))whl(1);whl(0)
#define asrtMLE(s) do if(!(s))whl(new int);whl(0)
#define asrtOLE(s) do if(!(s))whl(1)puts("OLE");whl(0)
#define asrtRE(s) do if(!(s))*(int*)0=0;whl(0)
#define runtime() (cerr)
#define input(in) freopen(in,"r",stdin)
#define output(out) freopen(out,"w",stdout)
#else
#define prt(x) cerr<<"第"<<__LINE__<<"行\t: "<<#x"\t="<<(x)<<endl
#define asrtWA(s) do if(!(s))cerr<<"assert("#s")"<<endl;whl(0)
#define asrtTLE(s) do if(!(s))cerr<<"assert("#s")"<<endl;whl(0)
#define asrtMLE(s) do if(!(s))cerr<<"assert("#s")"<<endl;whl(0)
#define asrtOLE(s) do if(!(s))cerr<<"assert("#s")"<<endl;whl(0)
#define asrtRE(s) do if(!(s))cerr<<"assert("#s")"<<endl;whl(0)
#define runtime() cerr<<"Used: "<<db(clock())/CLOCKS_PER_SEC<<"s"<<endl
#define input(in)
#define output(out)
#endif

typedef long long int lli;
typedef double db;
typedef const char* cstr;
typedef string str;
typedef vec<int> vi;
typedef vec<vi> vvi;
typedef vec<bool> vb;
typedef vec<vb> vvb;
typedef vec<str> vs;
typedef pr<int,int> pii;
typedef pr<lli,lli> pll;
typedef pr<db,db> pdd;
typedef map<int,int> mii;
typedef map<str,int> msi;
typedef map<char,int> mci;
typedef set<int> si;
typedef set<str> ss;
typedef que<int> qi;
typedef vec<pii> vpii;
typedef vec<pdd> vpdd;

int oo=(~0u)>>1;
lli ooll=(~0ull)>>1;
db inf=1e+10;
db eps=1e-10;
db gam=0.5772156649015328606;
db pi=acos(-1.0);
int dx[]={1,0,-1,0,1,-1,-1,1,0};
int dy[]={0,1,0,-1,1,1,-1,-1,0};
int MOD=1000000007;

template<typename type>inline bool cmax(type& a,const type& b){rtn a<b?a=b,true:false;}
template<typename type>inline bool cmin(type& a,const type& b){rtn b<a?a=b,true:false;}
template<typename type>inline type sqr(const type& x){rtn x*x;}
template<typename type>inline type mod(const type& x){rtn x%MOD;}
inline int sgn(const db& x){rtn (x>+eps)-(x<-eps);}
inline int dbcmp(const db& a,const db& b){rtn sgn(a-b);}
template<typename type>inline pr<type,type> operator-(const pr<type,type>& x){rtn mp(-x.x,-x.y);}
template<typename type>inline pr<type,type> operator+(const pr<type,type>& a,const pr<type,type>& b){rtn mp(a.x+b.x,a.y+b.y);}
template<typename type>inline pr<type,type> operator-(const pr<type,type>& a,const pr<type,type>& b){rtn mp(a.x-b.x,a.y-b.y);}
template<typename type>inline pr<type,type> operator*(const pr<type,type>& a,const type& b){rtn mp(a.x*b,a.y*b);}
template<typename type>inline pr<type,type> operator/(const pr<type,type>& a,const type& b){rtn mp(a.x/b,a.y/b);}
template<typename type>inline pr<type,type>& operator-=(pr<type,type>& a,const pr<type,type>& b){rtn a=a-b;}
template<typename type>inline pr<type,type>& operator+=(pr<type,type>& a,const pr<type,type>& b){rtn a=a+b;}
template<typename type>inline pr<type,type>& operator*=(pr<type,type>& a,const type& b){rtn a=a*b;}
template<typename type>inline pr<type,type>& operator/=(pr<type,type>& a,const type& b){rtn a=a/b;}
template<typename type>inline type cross(const pr<type,type>& a,const pr<type,type>& b){rtn a.x*b.y-a.y*b.x;}
template<typename type>inline type dot(const pr<type,type>& a,const pr<type,type>& b){rtn a.x*b.x+a.y*b.y;}
template<typename type>inline type gcd(type a,type b){if(b)whl((a%=b)&&(b%=a));rtn a+b;}
template<typename type>inline type lcm(type a,type b){rtn a*b/gcd(a,b);}
template<typename istream,typename first_type,typename second_type>inline istream& operator>>(istream& cin,pr<first_type,second_type>& x){rtn cin>>x.x>>x.y;}
template<typename ostream,typename first_type,typename second_type>inline ostream& operator<<(ostream& cout,const pr<first_type,second_type>& x){rtn cout<<x.x<<" "<<x.y;}
template<typename istream,typename type>inline istream& operator>>(istream& cin,vec<type>& x){rep(i,sz(x))cin>>x[i];rtn cin;}
template<typename ostream,typename type>inline ostream& operator<<(ostream& cout,const vec<type>& x){rep(i,sz(x))cout<<x[i]<<(i+1==sz(x)?"":" ");rtn cout;}
inline ostream& pdb(int prcs,db x){rtn cout<<setprecision(prcs)<<fixed<<(sgn(x)?(x):0);}
template<typename type>inline void bit_inc(vec<type>& st,int x,type inc){whl(x<sz(st))st[x]+=inc,x|=x+1;}
template<typename type>inline type bit_sum(const vec<type>& st,int x){type s=0;whl(x>=0)s+=st[x],x=(x&(x+1))-1;rtn s;}
template<typename type>inline type bit_kth(const vec<type>& st,int k){int x=0,y=0,z=0;whl((1<<(++y))<=sz(st));fdt(i,y-1,0){if((x+=1<<i)>sz(st)||z+st[x-1]>k)x-=1<<i;else z+=st[x-1];}rtn x;}
inline void make_set(vi& st){rep(i,sz(st))st[i]=i;}
inline int find_set(vi& st,int x){int y=x,z;whl(y!=st[y])y=st[y];whl(x!=st[x])z=st[x],st[x]=y,x=z;rtn y;}
inline bool union_set(vi& st,int a,int b){a=find_set(st,a),b=find_set(st,b);rtn a!=b?st[a]=b,true:false;}
template<typename type>inline void merge(type& a,type& b){if(sz(a)<sz(b))swap(a,b);whl(sz(b))a.ins(*b.begin()),b.ers(b.begin());}

struct Initializer
{
#ifndef DEBUG
	Initializer(){ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);}
#else
	~Initializer(){runtime();}
#endif
}initializer;

#define feach(e,s) for (__typeof__((s).begin()) e=(s).begin();e!=(s).end();++e)
#include <ext/rope>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/tag_and_trait.hpp>
using __gnu_cxx::rope;
template<typename key,typename value>class ext_map:public __gnu_pbds::tree<key,value,less<key>,__gnu_pbds::rb_tree_tag,__gnu_pbds::tree_order_statistics_node_update>{};
#define ctz __builtin_ctz
#define clz __builtin_clz
#define bc __builtin_popcount

bool dfs(int x,int y,int dir,int rest,vec<si>& xs,vec<si>& ys,vec<char>& path);
bool go(int x,int y,int dir,int rest,vec<si>& xs,vec<si>& ys,vec<char>& path)
{
	path[rest]="DRUL"[dir];
	int nx,ny;
	si::itr it;
	if (dir==0)
	{
		it=ys[y].upper_bound(x);
		if (it==ys[y].end()) rtn false;
		nx=*it;
		ny=y;
	}
	if (dir==1)
	{
		it=xs[x].upper_bound(y);
		if (it==xs[x].end()) rtn false;
		nx=x;
		ny=*it;
	}
	if (dir==2)
	{
		it=ys[y].upper_bound(x);
		if (it==ys[y].begin()) rtn false;
		--it;
		nx=*it;
		ny=y;
	}
	if (dir==3)
	{
		it=xs[x].upper_bound(y);
		if (it==xs[x].begin()) rtn false;
		--it;
		nx=x;
		ny=*it;
	}
	xs[nx].ers(ny);
	ys[ny].ers(nx);
	bool get=dfs(nx,ny,dir,rest,xs,ys,path);
	xs[nx].ins(ny);
	ys[ny].ins(nx);
	rtn get;
}
bool dfs(int x,int y,int dir,int rest,vec<si>& xs,vec<si>& ys,vec<char>& path)
{
	if (rest)
	{
		rest--;
		if (go(x,y,dir?dir-1:3,rest,xs,ys,path)) rtn true;
		if (go(x,y,dir,rest,xs,ys,path)) rtn true;
		if (go(x,y,dir+1==4?0:dir+1,rest,xs,ys,path)) rtn true;
		rtn false;
	}
	else
	{
		rev(path);
		cout<<str(all(path))<<endl;
		rev(path);
		rtn true;
	}
}

int main()
{
	int n,m;
	cin>>n>>m;
	vec<vec<char> > g(n,vec<char>(m));
	cin>>g;
	vpii lst;
	int x,y;
	rep(i,n) rep(j,m)
	{
		if (g[i][j]=='o') lst.pb(mp(i,j));
		else if (g[i][j]!='.') x=i,y=j;
	}
	vec<si> xs(n),ys(m);
	vec<char> path(sz(lst));
	rep(i,sz(lst)) xs[lst[i].x].ins(lst[i].y),ys[lst[i].y].ins(lst[i].x);
	if (g[x][y]=='D') dfs(x,y,0,sz(lst),xs,ys,path);
	if (g[x][y]=='R') dfs(x,y,1,sz(lst),xs,ys,path);
	if (g[x][y]=='U') dfs(x,y,2,sz(lst),xs,ys,path);
	if (g[x][y]=='L') dfs(x,y,3,sz(lst),xs,ys,path);
}

Measured memory_bytes: 1228