#include<iostream>
#include<vector>
#include<algorithm>
#include<chrono>
using namespace std;


int main()
{
    int pre_score;

    for (int i = 0; i < 1000; i++) {

        int si,sj,ti,tj;
        cin >> si >> sj >> ti >> tj;

        string ans="";
        if (si-ti<0) {
            for (int j = 0; j < ti-si; j++) ans += 'D';
        }
        else if (si-ti>0) {
            for (int j = 0; j < si-ti; j++) ans += 'U';
        }
        if (sj-tj<0) {
            for (int j = 0; j < tj-sj; j++) ans += 'R';
        }
        else if (sj-tj>0) {
            for (int j = 0; j < sj-tj; j++) ans += 'L';
        }

        cout << ans << endl;
        if (i==999) return 0;
        cin >> pre_score;
    }
}

#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for (int i = (s); i < (int)(n); i++)
#define pi 3.14159265359
#define all(i) i.begin(),i.end()
using namespace std;
const long long INF=1e9+7;
const string alp="abcdefghijklmnopqrstuvwxyz"; //26
const string ALP="ABCDEFGHIJKLMNOPQRSTUVWXYZ";
typedef long long ll;
typedef vector<ll> vl;
typedef vector<vector<ll>> vvl;
typedef pair<ll,ll> P;
typedef tuple<ll,ll,ll> T;
//const ll MOD=998244353LL;
//const ll MOD=1777777777LL;


int main() {
  long double sx,sy,gx,gy;
  cin>>sx>>sy>>gx>>gy;
  gy=-gy;
  long double k=(gx-sx)/(gy-sy);
  long double ans=sx-k*sy;
  cout<<fixed<<setprecision(30)<<ans<<endl;
}