https://www.lanqiao.cn/problems/602/learning/?page=1&first_category_id=1&second_category_id=3&name=%E8%BF%B7%E5%AE%AB

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<ll, ll> PII;
typedef vector<long long> VI;
#define rep(i,a,n) for (int i=a;i<=n;i++)
#define per(i,a,n) for (int i=a;i>=n;i--)
#define pb(i) push_back(i)
#define int long long
#define INF 0x3f3f3f3f
#define oz  998244353
#define endl '\n'
#define N 200010
const int mod = 1e9 + 7;


int p[N], si[N];
int find(int x) {
    if (x != p[x]) p[x] = find(p[x]);
    return p[x];
}
//size[find(b)] += size[find(a)];
//p[find(a)] = find(b);


bool st[35][50];
struct piont {
    int x, y;
    string road;

    f(int a, int b) {
        x = a;
        y = b;
    }
};
char ch[4] = {'D', 'L', 'R', 'U'};
int dx[4][2] = {1, 0, -0, -1, 0, 1, -1, 0};
char s[35][50];

void solve() {

    rep(i, 1, 30) {
        rep(j, 1, 50) {
            cin >> s[i][j];
        }
    }

    queue<piont> q;
    q.push({1, 1, ""});
    st[1][1] = 0;

    while (!q.empty()) {
        auto t = q.front();
        q.pop();

        if (t.x == 30 && t.y == 50) {
            cout << t.road << endl;
            return ;
        }

        for (int i = 0; i < 4; i ++) {
            int xx = t.x + dx[i][0], yy = t.y + dx[i][1];

            if(xx >= 1 && xx <= 30 && yy >= 1 && yy <= 50 && !st[xx][yy] && s[xx][yy] == '0'){

                piont qq = {xx, yy, t.road + ch[i]};
                st[xx][yy] = 1;

                q.push(qq);

            }
        }
    }

}

signed main() {

    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    int T = 1;
//  cin >> T;
    while (T --)

        solve();

    return 0;
}