# include <bits/stdc++.h>
using namespace std;
# define ll long long
# define ull unsigned long long
# define rep(i, f, t, ...) for (int i = f, ##__VA_ARGS__; i <= t; ++i)
# define red(i, f, t, ...) for (int i = f, ##__VA_ARGS__; i >= t; --i)
# define emb emplace_back
# define pb push_back
# define pii pair<int, int>
# define mkp make_pair
# define arr3 array<int, 3>
# define arr4 array<int, 4>
# define FILEIO(filename) freopen (filename".in", "r", stdin), freopen (filename ".out", "w", stdout)
# define ALL(vc) vc.begin ( ), vc.end ( )
# define N 25
# define M 405
template < class T > constexpr static T inf = numeric_limits < T > :: max ( ) / 2;

# ifndef __GEORGEYUCJR_READ__
# ifdef MACOS
# include "/Users/yzw/GeorgeYuOI/codes/cpp/georgeyucjr/debug/debug.hpp"
using namespace georgeyucjr;
# else
# define write(...) void(36)
# define bug(...) void(36)
# endif
# else
# warning Do not use debug.hpp.
# endif

bool Mst;

int n, m, cnt;
int vs[N][N], gr[M][4], dist[M][M], pre[M][M];
constexpr int _dx[4] = { -1, 0, 1, 0};
constexpr int _dy[4] = {0, 1, 0, -1};
constexpr char DRUL[5] = "URDL";

bool Med;

signed main() {
	ios_base :: sync_with_stdio ( false ), cin.tie ( nullptr ), cout.tie (nullptr);

	cin >> n >> m;
	vector < string > mp;
	mp.resize(n);
	for (auto&i : mp) cin >> i;
	cnt = 0;
	memset(vs, -1, sizeof vs);
	rep (i, 0, n - 1) rep (j, 0, m - 1) if (mp[i][j] == '1') vs[i][j] = cnt++;
	rep (x, 0, n - 1) rep (y, 0, m - 1, u)
	if (~(u = vs[x][y]))
		rep (d, 0, 3, dx, dy)
		gr[u][d] = (0 <= (dx = x + _dx[d]) && dx < n && 0 <= (dy = y + _dy[d]) && dy < m
		              && ~vs[dx][dy]) ? vs[dx][dy] : u;
	queue<pair<int, int>> que;
	queue < pii > q;
	memset(dist, -1, sizeof dist);
	memset(pre, -1, sizeof pre);
	rep (u, 0, cnt - 1) dist[u][u] = 0, q.emplace(u, u);
	while (!q.empty()) {
		auto [u, v] = q.front();
		q.pop();
		rep (d, 0, 3)
		for (auto uu : {u, gr[u][d ^ 2]}) if (gr[uu][d] == u)
			for (auto vv : {v, gr[v][d ^ 2]}) if (gr[vv][d] == v)
			if (!~dist[uu][vv]) {
				dist[uu][vv] = dist[u][v] + 1;
				pre[uu][vv] = d;
				q.emplace(uu, vv);
			}
	}
	rep (u, 0, cnt - 1) rep (v, 0, cnt - 1) assert ( ~ dist[u][v] );
	vector < int > vc(cnt); iota(ALL(vc), 0);
	string ans;
	while (vc.size() > 1) {
		int mn = cnt * cnt, posu = -1, posv = -1;
		rep (i, 0, SZ - 1, SZ = vc.size()) rep (j, i + 1, SZ - 1)
		if (mn > dist[vc[i]][vc[j]])
			mn = dist[vc[i]][vc[j]],
			posu = vc[i],
			posv = vc[j];
		for (int u = posu, v = posv, d = 0; u != v; )
			ans += DRUL[d = pre[u][v]], u = gr[u][d], v = gr[v][d], for_each(ALL(vc), [&](auto & x) {x = gr[x][d];});
		sort(ALL(vc)),
		     vc.erase(unique(ALL(vc)), vc.end());
	}
	cout << ans << endl;

# ifdef nACOS
	cerr << "nemory & Time Information : " << endl;
	cerr << "nemory : " << ( ( &ned ) - ( &nst ) ) * 1. / 1024. / 1024. << "nB" << endl;
	cerr << "Time : " << clock ( ) * 1. / CLOCKS_PER_SEC * 1000. << "ms" << endl;
# endif
	return 0;
}