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

// #define int long long // intで書いたけど心配なときにlong longに変換する
struct Fast {Fast(){std::cin.tie(0);ios::sync_with_stdio(false);}} fast;

/* short */
#define pb push_back
#define pf push_front
#define eb emplace_back
#define mp make_pair
#define Fi first
#define Se second
#define ALL(v) begin(v), end(v)
#define RALL(v) rbegin(v), rend(v)
#define X real()
#define Y imag()

/* REPmacro */
#define REPS(i, a, n) for (ll i = (a); i < (ll)(n); ++i)
#define REP(i, n) REPS(i, 0, n)
#define RREP(i, n) REPS(i, 1, n + 1)
#define DEPS(i, a, n) for (ll i = (a); i >= (ll)(n); --i)
#define DEP(i, n) DEPS(i, n, 0)
#define EACH(i, n) for (auto&& i : n)

/* debug */
#define debug(x) cerr << x << " " << "(L:" << __LINE__ << ")" << '\n';

/* alias */
using ll = long long;
using ull = unsigned long long;
using uint = unsigned int;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using pii = pair<int, int>;
using tiii = tuple<int, int, int>;
using vll = vector<ll>;
using vvll = vector<vll>;
using vvvll = vector<vvll>;
using plglg = pair<ll, ll>;
using tlglglg = tuple<ll, ll, ll>;
using D = double;
using P = complex<D>;
using vs = vector<string>;
template <typename T> using PQ = priority_queue<T>;
template <typename T> using minPQ = priority_queue<T, vector<T>, greater<T>>;

/* const */
const int INF = 1001001001;
const ll LINF = 1001001001001001001ll;
const int MOD = 1e9 + 7;
const D EPS = 1e-9;
const int dx[] = {0, 1, 0, -1, 1, -1, 1, -1}, dy[] = {1, 0, -1, 0, 1, -1, -1, 1};

/* func */
inline bool inside(int y, int x, int H, int W) {return y >= 0 && x >= 0 && y < H && x < W;}
inline int in() {int x; cin >> x; return x;}
inline ll IN() {ll x; cin >> x; return x;}
inline vs split(const string& t, char c) {vs v; stringstream s(t); string b; while(getline(s, b, c)) v.eb(b); return v;}
template <typename T> inline bool chmin(T& a, const T& b) {if (a > b) a = b; return a > b;}
template <typename T> inline bool chmax(T& a, const T& b) {if (a < b) a = b; return a < b;}
template <typename T, typename S> inline void print(const pair<T, S>& p) {cout << p.first << " " << p.second << endl;}
template <typename T> inline void print(const T& x) {cout << x << endl;}
template <typename T, typename S> inline void print(const vector<pair<T, S>>& v) {for (auto&& p : v) print(p);}
template <typename T> inline void print(const vector<T>& v, string s = " ") {REP(i, v.size()) cout << v[i] << (i != (ll)v.size() - 1 ? s : "\n");}
inline void yesno(bool ok, string yes = "Yes", string no = "No") {cout << (ok?yes:no) << endl;}

signed main() {
    //my-code
    string S; cin >> S;
    deque<char> T; T.clear();
    bool is_turn = false;

    REP(i, S.length()) {
        if (S[i] == 'R') {
            if (is_turn) {
                is_turn = false;
            } else {
                is_turn = true;
            }
        } else {
            if (is_turn) {
                if (T.empty() || T.front() != S[i]) {
                    T.pf(S[i]);
                } else {
                    T.pop_front();
                }
            } else {
                if (T.empty() || T.back() != S[i]) {
                    T.pb(S[i]);
                } else {
                    T.pop_back();
                }
            }
        }
    }

    deque<char> ans;
    ans.clear();

    for (char c : T) {
        if (is_turn) {
            ans.pf(c);
        } else {
            ans.pb(c);
        }
    }

    for (char c : ans) {
        cout << c;
    }
    cout << endl;

    return 0;
}

// https://github.com/kurokoji/.cpp-Template/wiki テンプレートについて
// http://www.creativ.xyz/dump-cpp-652 dump()について
// https://gist.github.com/rigibun/7905920 色々
                              ////JAI SHREE RAM////
#include <iostream>
#include<bits/stdc++.h>
using namespace std;
const long long int INF = (long long)1e15;
const long long int mod = 1e9+7;
#define ll long long
#define f(i,a,b) for(int i=a;i<b;i++)
#define pb push_back
#define all(c) c.begin(),c.end()
#define rall(c) c.rbegin(),c.rend()
#define yes cout<<"YES\n"
#define no cout<<"NO\n"
#define sd second
#define ft first
//
bool cmp(const pair<int,int> &a, const pair<int,int> &b)
{
    //return (a.sd>=b.sd);
    return abs(a.ft)+abs(a.sd) < abs(b.ft)+abs(b.sd);
}
//void prime(vector<ll>&v,ll n)
//{
//    for(ll i=2;i*i<=n;i++)
//    {
//        if(n%i==0)
//        {
//            v.pb(i);
//            if(n/i!=i) v.pb(n/i);
//        }
//    }
//    v.pb(n);
//}
//int binPow(int a, int n)
//{
//    int res=1;
//    while(n)
//    {
//        if(n&1)
//            res=(1ll*res*a)%mod;
//        a=(1ll*a*a)%mod;
//        n>>=1;
//    }
//    return res;
//}
//int C(int n,int k,ll fact[],ll inv[])
//{
//    if(k>n) return 0;
//    int res = (1ll*fact[n]*inv[k])%mod;
//    res=(1ll*res*inv[n-k])%mod;
//    //cout<<res<<endl;
//    return res;
//}

void solve()
{
    ll n;cin>>n;
    ll x=1;
    for(x=1;x<=n+2;x++)
    {
        if(1ll*x*(x+1)>=2*n)
        {
            cout<<x<<endl;
            return;
        }
    }
}

int main()
{
    //ios_base::sync_with_stdio(false); cin.tie(0);cout.tie(0);
    int t=1;
    //cin>>t;

    while(t--)
    {
        solve();
    }
    return 0;
}

