Problem:
Score: 200 points

Problem Statement

Takahashi will do a tap dance. The dance is described by a string S where each character is L, R, U, or D. These characters indicate the positions on which Takahashi should step. He will follow these instructions one by one in order, starting with the first character.

S is said to be easily playable if and only if it satisfies both of the following conditions:

Every character in an odd position (1-st, 3-rd, 5-th, \ldots) is R, U, or D.

Every character in an even position (2-nd, 4-th, 6-th, \ldots) is L, U, or D.

Your task is to print Yes if S is easily playable, and No otherwise.

Constraints

S is a string of length between 1 and 100 (inclusive).

Each character of S is L, R, U, or D.

Input

Input is given from Standard Input in the following format:

S

Output

Print Yes if S is easily playable, and No otherwise.

Sample Input 1

RUDLUDR

Sample Output 1

Yes

Every character in an odd position (1-st, 3-rd, 5-th, 7-th) is R, U, or D.

Every character in an even position (2-nd, 4-th, 6-th) is L, U, or D.

Thus, S is easily playable.

Sample Input 2

DULL

Sample Output 2

No

The 3-rd character is not R, U, nor D, so S is not easily playable.

Sample Input 3

UUUUUUUUUUUUUUU

Sample Output 3

Yes

Sample Input 4

ULURU

Sample Output 4

No

Sample Input 5

RDULULDURURLRDULRLR

Sample Output 5

Yes

Solution in C++ (GCC 9.2.1) (judge verdict: Accepted)

#include <bits/stdc++.h>
#define FASTIO ios::sync_with_stdio(false);cin.tie(0);
#define ADD +
#define SUBTRACT -
#define MULTIPLY *
#define DIVIDE /
#define MOD %
#define INCREMENT(x) ++x
#define DECREMENT(x) --x
#define in(a,b) cin>>a>>b;
#define out(a,b) cout<<a<<endl<<b<<endl;
#define scan(a) scanf("%d",&a);
#define print(a) printf("%d\n",a);
#define scanii(a,b) scanf("%d %d",&a,&b);
#define printii(a,b) printf("%d\n%d\n",a,b);
#define scaniii(a,b,c) scanf("%d %d %d",&a,&b,&c);
#define pub push_back
#define pob pop_back
#define puf push_front
#define pof pop_front
#define ll long long
#define ull unsigned long long
#define sll signed long long
#define pi acos(-1)
#define mod 1000000007
#define TRUE 1
#define FALSE 0
#define ZERO 0
#define MP make_pair
#define F first
#define S second
#define f1(i,a) for(int i=0;i<a;++i)
#define f2(i,a) for(int i=a-1;i>=0;--i)
#define en puts("");
#define elif else if
typedef ll int lli;
typedef sll int slli;
typedef ull int ulli;
const int sz=10000;
using namespace std;

int clue();
int result();
void show();
bool check(int n) {
    for(int i=2;i*i<=n;++i) {
        if(n%i==0)
        return false;
    }
    return true;
}


// bool cmp(pair<int,int>p,pair<int,int>q) {
//     // return p.first>q.first;//descending by first
//     // return p.first<q.first;//ascending by first
//     // return p.second>q.second;//descending by second
//     return p.second<q.second;//ascending by second
// }

bool cmp(int p,int q) {
    return p>q;//descending
    // return p<q;//ascending
}


int main() {

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

    return 0;
}
int clue() {

    string s;
    cin>>s;
    int n=s.size();
    int det=0;

    f1(i,n) {
        int x=i+1;
        if(x%2==0) {
            if(s[i]=='R')++det;
        }
        else
        {
            if(s[i]=='L')++det;
        }
    }
    (!det)?cout<<"Yes"<<endl:cout<<"No"<<endl;
    
    return 0;
}