/*set加速维护*/

#include<iostream>

#include<cstdio>

#include<cstring>

#include<set>

#define maxn 100010

using namespace std;

set<int>s;

set<int>::iterator p;

int n,m,a[maxn],top;

char c[];

int init()

{

    int x=,f=;char s=getchar();

    while(s<''||s>''){if(s=='-')f=-;s=getchar();}

    while(s>=''&&s<=''){x=x*+s-'';s=getchar();}

    return x*f;

}

int main()

{

    n=init();m=init();int x;

    s.insert();s.insert(n+);

    while(m--)

      {

          scanf("%s",c);

          if(c[]=='D')

            {

                x=init();a[++top]=x;

                s.insert(x);

          }

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

          {

              if(top==)continue;

              p=s.find(a[top]);

              top--;s.erase(p);

          }

        else if(c[]=='Q')

          {

              int r;x=init();

              p=s.lower_bound(x);

              if(*p==x)

              {

                  printf("0\n");

                  continue;

              }

            r=*p-*(--p);

            printf("%d\n",r-);

          }

      }

    return ;

}