#include<algorithm>
#include<iostream>
#include<iomanip>
#include<stdio.h>
#include<bitset>
#include<vector>
#include<string>
#include<queue>
#include<cmath>
#include<ctime>
#include<stack>
#include<map>
#include<set>
using namespace std;
typedef long long LL;
typedef long double LD;
typedef pair<LL,LL> PLL;
typedef pair<LD,LD> PDD;
typedef pair<int,int> PII;
typedef pair<PII,PII> PPII;
#define PRINT(a) cerr<<#a<<" = "<<(a)<<'\n'
#define B_E(a) a.begin(), a.end()
#define PB push_back
#define MP make_pair
#define S second
#define F first
inline void file() {
    #ifdef _WIN32
        srand(time(NULL));
        return;
    #endif

    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);

    if (0) {
        freopen(".in",  "r", stdin);
        freopen(".out", "w", stdout);
    }
}
inline void read(int& n) {
    #define nxt h = getchar_unlocked()
    #define nxt h = getchar()
    char h; n = 0;
    for (nxt; h<'0' || h>'9'; nxt);
    for (; h>='0' && h<='9'; nxt)
        n = n*10 + h-'0';
    #undef nxt
}





const clock_t MAXT = (100*CLOCKS_PER_SEC)/1000;
const int   PX[8] = {1,0,-1,0,  1,1,-1,-1},
            PY[8] = {0,1,0,-1,  -1,1,1,-1},
            SZ = 400,
            N = 1e4 + 10 + 2*SZ,
            M = 1e5 + 10,
            INF = 1e9,
            MOD = 1e9 + 7;
const LL    INFL = 1e18,
            MODL = 1e9 + 7;
const LD    EPS = 1e-6;

inline int rnd(int l = 0, int r = INF) {
    unsigned ans = rand();
    ans = (ans<<8) ^ rand();
    ans = (ans<<8) ^ rand();
    ans = (ans<<8) ^ rand();
    ans %= r-l+1;
    return int(ans + l);
}








int mxx,mxy,bx[N],by[N];
PLL dp[N/SZ+1][N/SZ+1][SZ+1];
pair<char,char> dp_p[N/SZ+1][N/SZ+1][SZ+1];
LL a[SZ+1][SZ+1],buf[SZ+1][SZ+1];
char p[SZ+1][SZ+1];


inline void up(int& x, int y) {
    if ( x > y ) x= y;
}

void calc_cell(int y, int x) {
    cerr<<" 1111"<<endl;
    for (int i=0; i<=SZ; ++i)
    for (int j=0; j<=SZ; ++j) {
        int m = i*SZ+y;
        int n = j*SZ+x;
        a[i][j] = (by[m]+n) ^ (bx[n]+m);
    }
    cerr<<" 2222"<<endl;
    for (int i=0; i<=SZ; ++i) {
        buf[0][i] = dp[y][x][i].F;
        buf[i][0] = dp[y][x][i].S;
        p[0][i] = dp_p[y][x][i].F;
        p[i][0] = dp_p[y][x][i].S;
    }
    cerr<<" 3333"<<endl;
    for (int i=1; i<=SZ; ++i)
    for (int j=1; j<=SZ; ++j) {
        buf[i][j] = a[i][j];

        if ( buf[i-1][j] < buf[i][j-1] ) {
            buf[i][j] += buf[i-1][j];
            p[i][j] = 1;
        } else {
            buf[i][j] += buf[i][j-1];
            p[i][j] = 0;
        }

    }
    cerr<<" 4444"<<endl;
}

inline void push_dp(int y, int x) {
    for (int i=0; i<=SZ; ++i) {
        dp[y][x+1][i].S = buf[i][SZ];
        dp_p[y][x+1][i].S = p[i][SZ];

        dp[y+1][x][i].F = buf[SZ][i];
        dp_p[y+1][x][i].F = p[SZ][i];
    }
}

inline void get_path(vector<char>& path, int& block_y, int& block_x, int& y, int& x)
{
    calc_cell(block_y, block_x);
    while ( x || y ) {
        path.PB( p[y][x] );

        if ( p[x][y] )
            --y;
        else
            --x;
    }

    if ( !y ) {--block_y; y = SZ;}
    if ( !x ) {--block_x; x = SZ;}

}

void solve()
{

    for (int i=0; i*SZ<=mxy; ++i)
    for (int j=0; j*SZ<=mxx; ++j)
        for (int x=0; x<SZ; ++x)
            dp[i][j][x] = MP(INFL, INFL);

    dp[0][0][0] = MP(0,0);
    dp[0][0][1] = MP(0,INFL);

    for (int i=0; i*SZ<=mxy; ++i)
    for (int j=0; j*SZ<=mxx; ++j) {
        calc_cell(i,j);
        push_dp(i,j);
    }




    vector<char> path;
    int x,y,block_x,block_y;
    block_y = mxy/SZ;
    block_x = mxx/SZ;
    y = mxy%SZ;
    x = mxx%SZ;

    while ( block_x || block_y )
        get_path(path, block_y, block_x, y, x);
    path.pop_back();
    path.pop_back();

    reverse(B_E(path));

    for (char i:path)
        if (i)
            cout<<'D';
        else
            cout<<'R';


}


main()
{

    cin>>mxy>>mxx;
    for (int i=1; i<=mxy; ++i) cin>>by[i];
    for (int i=1; i<=mxx; ++i) cin>>bx[i];

    calc_cell(0,0);
    for (int i=0; i<=mxy; ++i) {
        for (int j=0; j<=mxy; ++j)
            cerr<<setw(3)<<a[i][j];
        cerr<<'\n';
    }
    cerr<<'\n';

    for (int i=0; i<=mxy; ++i) {
        for (int j=0; j<=mxy; ++j)
            cerr<<setw(3)<<buf[i][j];
        cerr<<'\n';
    }
    cerr<<'\n';
    return 0;

    solve();














































}