#include <bits/stdc++.h>
using namespace std;
using LL = long long;
constexpr int mod = 1e9 + 7;

void solve() {
    int n, m;
    cin >> n >> m;
    vector<string> s(n);
    int sx = 0, sy = 0;
    for (int i = 0; i < n; i++) {
        cin >> s[i];
        for (int j = 0; j < m; j++) {
            if (s[i][j] == '1') {
                sx = i;
                sy = j;
            }
        }
    }

    queue<tuple<string, int, int>> q;
    vector vis(n, vector(m, 0));
    q.emplace("", sx, sy);
    int dx[4] = {-1, 1, 0, 0};
    int dy[4] = {0, 0, -1, 1};
    string d = "DURL";

    vector<string> v;
    while (!q.empty()) {
        auto [str, x, y] = q.front();
        q.pop();

        if (vis[x][y]) continue;
        vis[x][y] = 1;

        v.push_back(str);

        for (int i = 0; i < 4; i++) {
            int nx = x + dx[i];
            int ny = y + dy[i];
            if (nx < 0 || nx >= n || ny < 0 || ny >= m || s[nx][ny] == '0' || vis[nx][ny]) {
                continue;
            }
            q.emplace(str + d[i], nx, ny);
        }
    }
    map<int, vector<string>, greater<>> mp;
    for (int i = v.size() - 1; i >= 0; i--) {
        auto &x = v[i];
        reverse(x.begin(), x.end());
        for (auto c : d) {
            mp[count(x.begin(), x.end(), c)].push_back(x);
        }
    }

    for (auto [k, v] : mp) {
        for (auto x : v) {
            cout << x;
        }
    }
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    while (t--) {
        solve();
    }
    return 0;
}