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

using namespace std;

const int N = 6e5 + 10, M = 25 * N;
int s[N];
int tr[M][2], ver[M];
int root[N], idx;

void insert(int k, int p, int q) {
    for (int i = 23; ~i; i--) {
        int u = s[k] >> i & 1;
        tr[q][u ^ 1] = tr[p][u ^ 1]; //复制
        tr[q][u] = ++idx;            //创建
        ver[tr[q][u]] = k;           //记录版本
        q = tr[q][u], p = tr[p][u];
    }
}

int query(int p, int l, int c) {
    for (int i = 23; ~i ; i--) {
        int u = c >> i & 1;
        if (tr[p][u ^ 1] && ver[tr[p][u ^ 1]] >= l)
            p = tr[p][u ^ 1];
        else
            p = tr[p][u];
    }
    return c ^ s[ver[p]]; // p:最终停留在的异或和最大值终点处,ver[p]这是哪个版本放进来的？,s[ver[p]]=S_{p-1}
}

int main() {
    ios::sync_with_stdio(false), cin.tie(0);
    int n, m;
    cin >> n >> m;

    // 0号版本,用于处理类似于S[1]-S[0]这样的递推边界值
    root[0] = ++idx;
    insert(0, 0, root[0]);

    for (int i = 1; i <= n; i++) {
        int x;
        cin >> x;
        root[i] = ++idx;
        s[i] = s[i - 1] ^ x; //原数组不重要，异或前缀和数组才重要
        insert(i, root[i - 1], root[i]);
    }

    while (m--) {
        char op;
        cin >> op;
        if (op == 'A') {
            int x;
            cin >> x;
            n++;

            root[n] = ++idx;
            s[n] = s[n - 1] ^ x;
            insert(n, root[n - 1], root[n]);
        } else {
            int l, r, x;
            cin >> l >> r >> x;
            printf("%d\n", query(root[r - 1], l - 1, s[n] ^ x));
        }
    }
    return 0;
}