/* ***********************************************

 Author        :kuangbin

 Created Time  :2013/8/22 13:38:35

 File Name     :F:\2013ACM练习\2013多校10\1004.cpp

 ************************************************ */

 #include <stdio.h>

 #include <string.h>

 #include <iostream>

 #include <algorithm>

 #include <vector>

 #include <queue>

 #include <set>

 #include <map>

 #include <string>

 #include <math.h>

 #include <stdlib.h>

 #include <time.h>

 using namespace std;

 const int MAXN = ;

 int a[MAXN];

 int next[MAXN],pre[MAXN],tot;

 int NewNode()

 {

     next[tot] = -;

     pre[tot] = -;

     tot++;

     return tot-;

 }

 int root;

 int sum[MAXN];

 vector<int>vec;

 int now;

 int n;

 void init()

 {

     tot = ;

     root = NewNode();

     vec.clear();

     n = now = ;

 }

 void I(int x)

 {

     n++;

     int t = NewNode();

     a[t] = x;

     pre[t] = now;

     next[t] = next[now];

     if(next[now] != -)pre[next[now]] = t;

     next[now] = t;

     now = t;

     if(n == )

     {

         sum[n] = x;

         vec.push_back(n);

     }

     else

     {

         sum[n] = sum[n-] + x;

         int sz = vec.size();

         if(sum[n] > sum[vec[sz-]])

             vec.push_back(n);

     }

 }

 void D()

 {

     if(n == )return;

     int sz = vec.size();

     if(vec[sz-] == n)

         vec.pop_back();

     n--;

     int t = pre[now];

     next[t] = next[now];

     if(next[now] != -)pre[next[now]] = t;

     now = t;

 }

 void L()

 {

     if(n == )return;

     int sz = vec.size();

     if(vec[sz-] == n)

         vec.pop_back();

     now = pre[now];

     n--;

 }

 void R()

 {

     if(next[now] == -)return;

     n++;

     now = next[now];

     if(n == )

     {

         sum[n] = a[now];

         vec.push_back(n);

     }

     else

     {

         int sz = vec.size();

         sum[n] = sum[n-] + a[now];

         if(sum[n] > sum[vec[sz-]])

             vec.push_back(n);

     }

 }

 int Q(int k)

 {

     int sz = vec.size();

     if(vec[sz-] <= k)

         return sum[vec[sz-]];

     int t = upper_bound(vec.begin(),vec.end(),k) - vec.begin();

     return sum[vec[t-]];

 }

 int main()

 {

     //freopen("in.txt","r",stdin);

     //freopen("out.txt","w",stdout);

     int M;

     int x;

     char op[];

     while(scanf("%d",&M) == )

     {

         init();

         while(M--)

         {

             scanf("%s",&op);

             if(op[] == 'I')

             {

                 scanf("%d",&x);

                 I(x);

             }

             else if(op[] == 'D')

                 D();

             else if(op[] == 'L')

                 L();

             else if(op[] == 'R')

                 R();

             else

             {

                 scanf("%d",&x);

                 printf("%d\n",Q(x));

             }

         }

     }

     return ;

 }