#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#define rep(a, b, c) for(int (a) = (b); (a) <= (c); ++ (a))
#define per(a, b, c) for(int (a) = (b); (a) >= (c); -- (a))
using namespace std;

const int N = 50010;

int n, m;
int stk[N], top;
bool in_s[N];

struct SplaY {
    int tot, fa[N], ch[N][2], val[N], siz[N], cnt[N], root;
    
    int get_node(int w) {
        fa[ ++ tot] = 0;
        val[tot] = w;
        siz[tot] = cnt[tot] = 1;
        ch[tot][0] = ch[tot][1] = 0;
        return tot;
    }
    
    void upd(int u) {
        siz[u] = siz[ch[u][0]] + siz[ch[u][1]] + cnt[u];
    }
    
    void rot(int x) {
        int y = fa[x], z = fa[y], k = ch[y][1] == x, w = ch[x][k ^ 1];
        if(z) ch[z][ch[z][1] == y] = x; fa[x] = z;
        fa[fa[ch[ch[x][k ^ 1] = y][k] = w] = y] = x;
        upd(y), upd(x);
    }
    
    void spl(int x, int aim) {
        while(fa[x] != aim) {
            int y = fa[x], z = fa[y];
            if(z != aim) rot((ch[z][1] == y) ^ (ch[y][1] == x) ? x : y);
            rot(x);
        }
        if(!aim) root = x;
    }
    
    void ins(int w) {
        int u = root, y;
        while(u && val[u] != w) y = u, u = ch[u][w > val[u]];
        if(u) ++ cnt[u];
        else {
            u = get_node(w);
            if(y) ch[y][w > val[y]] = u;
            fa[u] = y;
        }
        spl(u, 0);
    }
    
    int getu(int w) {
        int u = root;
        while(val[u] != w && ch[u][w > val[u]]) u = ch[u][w > val[u]];
        return u;
    }
    
    int get_pr(int w) {
        int u = getu(w);
        if(val[u] < w) return u;
        spl(u, 0);
        u = ch[u][0];
        while(ch[u][1]) u = ch[u][1];
        return u;
    }
    
    int get_nt(int w) {
        int u = getu(w);
        if(val[u] > w) return u;
        spl(u, 0);
        u = ch[u][1];
        while(ch[u][0]) u = ch[u][0];
        return u;
    }
    
    void del(int w) {
        int pr = get_pr(w), nt = get_nt(w);
        spl(pr, 0), spl(nt, pr);
        int u = ch[nt][0];
        if(cnt[u] > 1) -- cnt[u], upd(u);
        else ch[nt][0] = 0;
        upd(nt), upd(pr);
    }
}SP;

int main() {
    scanf("%d%d", &n, &m);
    SP.ins(0), SP.ins(n + 1);
    while(m -- ) {
        char op[2];
        scanf("%s", op);
        if(*op == 'D') {
            int x;
            scanf("%d", &x);
            SP.ins(x);
            stk[ ++ top] = x;
            in_s[x] = true;
        }
        else if(*op == 'R') {
            int x = stk[top -- ];
            SP.del(x);
            in_s[x] = false;
        }
        else {
            int x;
            scanf("%d", &x);
            if(in_s[x]) puts("0");
            else printf("%d\n", SP.val[SP.get_nt(x)] - SP.val[SP.get_pr(x)] - 1);
        }
    }
    return 0;
}