1 #include<bits/stdc++.h>
 2 using namespace std;
 3 typedef long long ll;
 4 const int N=2000005;
 5 ll t,x,y,nx,ny;
 6 int n,l[N],r[N],len;
 7 struct node{ll ty,tz,x;node(){} node(ll A,ll B,ll C){ty=A;tz=B;x=C;}}a[N],b[N];
 8 bool operator < (const node &A,const node &B) {return A.ty<B.ty;}
 9 ll ceil(ll x,ll y)
10 {
11     if (x<0) x=-x,y=-y;
12     if (x==0) return 0;
13     if (y>0) return (x-1)/y+1;
14     else return x/y;
15 }
16 ll floor(ll x,ll y)
17 {
18    if (x<0) x=-x,y=-y;
19    if (x==0) return 0;
20     if (y>0) return x/y;
21     else return (x-1)/y-1;
22 }
23 void solve(node *a,int *ans)
24 {
25     sort(a+1,a+n+1);
26     ll L=0,R=len;
27     a[n+1]=node(len,-1,0);//设置边界!!!
28     for (int i=0;i<=n;i++)//要统计入最后一个限制S[len]=0-S*(-1)
29     {
30         ll d=a[i+1].ty-a[i].ty,q=a[i+1].x-a[i].x,p=a[i].tz-a[i+1].tz;
31         if (p>0)
32         {
33             L=max(L,ceil(-q,p));
34             R=min(R,floor(d-q,p));
35         }else if (p<0) {
36             L=max(L,ceil(d-q,p));
37             R=min(R,floor(-q,p));
38         }
39         if (L>R||p==0&&(q<0||q>d)) {puts("NO");exit(0);}
40     }
41     ll s=L,si=0;
42     for (int i=0,j=1;i<=n;i++)
43     {
44         si=(a[i+1].x-s*a[i+1].tz)-(a[i].x-s*a[i].tz);
45         while (si--) ans[j++]=1;
46         j=a[i+1].ty+1;//a[i+1]而不是a[i]
47     }
48 }
49 int main()
50 {
51     scanf("%d%d",&n,&len);
52     for (int i=1;i<=n;i++)
53     {
54         scanf("%lld%lld%lld",&t,&x,&y);
55         nx=x+y+t;ny=x-y+t;
56         if (nx&1) return puts("NO"),0;
57         nx/=2;ny/=2;
58         a[i]=node(t%len,t/len,nx);
59         b[i]=node(t%len,t/len,ny);
60     }
61     solve(a,l);
62     solve(b,r);
63     for (int i=1;i<=len;i++)
64       printf("%c","LDUR"[l[i]<<1|r[i]]);//此题的方向与常识相异！
65     return 0;
66 }