#include <iostream>
#include <cstring>
#include <cstdio>
#include <algorithm>

using namespace std;

const int N = 600005, M = N * 23;

int n, m;
int s[N];
int tr[M][2], root[N], idx;
int max_id[M];

void insert(int i,int k,int p,int q){
    if(k < 0){
        max_id[q] = i;
        return ;
    }
    int v = s[i] >> k & 1;
    if(p) tr[q][v ^ 1] = tr[p][v ^ 1];
    tr[q][v] = ++ idx;
    insert(i, k - 1, tr[p][v], tr[q][v]);
    max_id[q] = max(max_id[tr[q][0]], max_id[tr[q][1]]);
}

int query(int now, int val, int lim){
    for(int i = 23;~i;i -- ){
        int v = val >> i & 1;
        if(max_id[tr[now][v ^ 1]] >= lim) now = tr[now][v ^ 1];
        else now = tr[now][v];
    }
    return val ^ s[max_id[now]];
}

int main(){

    scanf("%d%d", &n, &m);

    max_id[0] = -1;
    // insert 0
    root[0] = ++ idx;
    insert(0, 23, 0, root[0]);
    for (int i = 1; i <= n; i ++ ){
        int x;
        scanf("%d", &x);
        s[i] = s[i - 1] ^ x;
        root[i] = ++ idx;
        insert(i, 23, root[i - 1], root[i]);
    }

    char op[2];
    int l, r, x;
    while (m -- ){
        scanf("%s", op);
        if (*op == 'A'){
            scanf("%d", &x);
            n ++ ;
            s[n] = s[n - 1] ^ x;
            root[n] = ++ idx;
            insert(n, 23, root[n - 1], root[n]);
        }
        else{
            scanf("%d%d%d", &l, &r, &x);
            printf("%d\n", query(root[r - 1], s[n] ^ x, l - 1));    
        }
    }


    return 0;
}