#include<bits/stdc++.h>

using namespace std;

int main()
{
    char ch[1010];
    int len,i,x;
    cin>>ch;
    len=strlen(ch);
    for(i=0;i<len;i++){
        x=i+1;
        if(x%2==0){
            if(ch[i]>=97 && ch[i]<=122){
                cout<<"No"<<"\n";
                return 0;
            }
        }
        else{
            if(ch[i]>=65 && ch[i]<=90){
                cout<<"No"<<"\n";
                return 0;
            }
        }
    }
    cout<<"Yes"<<"\n";

    return 0;
}

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define rng(i, a, b) for (int i = int(a); i < int(b); ++i)
#define rep(i, b) rng(i, 0, b)
#define gnr(i, a, b) for (int i = int(b) - 1; i >= int(a); --i)
#define per(i, b) gnr(i, 0, b)
#define all(obj) begin(obj), end(obj)
#define allr(obj) rbegin(obj), rend(obj)
#define cinv(a) rep(i, (int)a.size()) cin >> a[i]
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()

typedef long long ll;
typedef pair<int, int> Pi;
typedef vector<Pi> vp;
typedef vector<vp> vvp;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<char> vc;
typedef vector<vc> vvc;
typedef vector<bool> vb;
typedef vector<vb> vvb;

template <typename T> bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; }
template <typename T> bool chmin(T &a, const T &b) { if (a > b) { a = b; return true; } return false; }
template <typename T> using min_priority_queue = priority_queue<T, vector<T>, greater<T>>;

const int di[] = {0, -1, 0, 1};
const int dj[] = {1, 0, -1, 0};
const int MOD = 1e9 + 7;
const int INF = 1e9;
const ll LINF = 1e15;
const long double eps = 1e-10;
const char nl = '\n';

ll power(ll a, ll b) { return b ? power(a * a % MOD, b / 2) * (b % 2 ? a : 1) % MOD : 1; }

ll C(int n, int k)
{
	ll x = 1, y = 1;
	for (int i = 1; i <= k; ++i)
	{
		x = x * (n - i + 1) % MOD;
		y = y * i % MOD;
	}
	return x * power(y, MOD - 2) % MOD;
}

struct UF
{
	vi d;
	UF(int n) : d(n, -1) {}
	int root(int x)
	{
		if (d[x] < 0)
			return x;
		return d[x] = root(d[x]);
	}
	bool unite(int x, int y)
	{
		x = root(x);
		y = root(y);
		if (x == y)
			return false;
		if (d[x] > d[y])
			swap(x, y);
		d[x] += d[y];
		d[y] = x;
		return true;
	}
	bool same(int x, int y) { return root(x) == root(y); }
	int size(int x) { return -d[root(x)]; }
};

int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	string s; cin >> s;
	deque<char> t;
	int rev = 0;
	rep(i, sz(s))
	{
		if (s[i] == 'R') rev = 1 - rev;
		else if (rev) t.push_front(s[i]);
		else t.push_back(s[i]);
	}
	string ans = "";
	if (!sz(t))
	{
		cout << ans << nl;
		return 0;
	}
	ans += t.front();
	t.pop_front();
	while (sz(t))
	{
		if (sz(ans) && t.front() == ans.back())
		{
			ans.pop_back();
		}
		else
		{
			ans += t.front();
		}
		t.pop_front();
	}
	if (rev && sz(ans)) reverse(all(ans));
	cout << ans << nl;
}
