#include <bits/stdc++.h>

using namespace std;

const int N = 4e5 + 5, B = 256, S = N / B + 5;

int tr[B], _lg[B];

int wh(int x) {
    return ((x - 1) >> 8) + 1;
}

int n, c[N];

int f(int x) {
    return ((~x) & (-~x)) * 2 - 1;
}

int b[2][N], lz[S], sum[2][S];
int wgt[S][B];
bool cnt[S][2][B];
vector<int> hv[S][B];

int ct[B << 1], g[2][B << 1];

void push(int x) {
    for (int i = 0; i < 2; ++i) {
        memset(ct, 0, sizeof(ct));
        for (int j = 0; j < B; ++j) {
            if (cnt[x][i][j]) ct[tr[j] + B] = 1;
        }
        for (int j = B - 1; j; --j) ct[j] = ct[j << 1] ^ ct[j << 1 | 1];
        g[i][1] = ct[1];
        for (int j = 2; j < B * 2; ++j) {
            g[i][j] = g[i][j >> 1];
            if (j < B && ct[j]) g[i][j] ^= 1 << _lg[j];
        }
    }
    for (int i = (x - 1) * B + 1; i <= x * B && i <= n; ++i) {
        for (int j = 0; j < 2; ++j) {
            b[j][i] ^= g[j][tr[~c[i] & (B - 1)] + B];
        }
        c[i] += lz[x];
    }
    lz[x] = 0;
}

void build(int x) {
    sum[0][x] = sum[1][x] = 0;
    memset(cnt[x], 0, sizeof(cnt[x]));
    memset(wgt[x], 0, sizeof(wgt[x]));
    for (int i = 0; i < B; ++i) hv[x][i].clear();
    memset(ct, 0, sizeof(ct));
    for (int i = (x - 1) * B + 1; i <= x * B && i <= n; ++i) {
        sum[0][x] ^= b[0][i], sum[1][x] ^= b[1][i];
        ct[tr[c[i] & (B - 1)] + B] ^= 1;
        hv[x][~c[i] & (B - 1)].push_back(i);
    }
    for (int j = B - 1; j; --j) ct[j] = ct[j << 1] ^ ct[j << 1 | 1];
    g[0][1] = ct[1];
    for (int j = 2; j < B * 2; ++j) {
        g[0][j] = g[0][j >> 1];
        if (j < B && ct[j]) g[0][j] ^= 1 << _lg[j];
    }
    for (int j = 0; j < B; ++j) wgt[x][j] = g[0][tr[~j & (B - 1)] + B];
}

void opt(int z, int x) {
    sum[z][x] ^= wgt[x][lz[x] & (B - 1)], cnt[x][z][lz[x] & (B - 1)] ^= 1;
    for (auto v : hv[x][lz[x] & (B - 1)]) {
        b[z][v] ^= f(c[v] + lz[x]) ^ (B - 1);
        sum[z][x] ^= f(c[v] + lz[x]) ^ (B - 1);
    }
    ++lz[x];
}

void modify(int z, int l, int r) {
    if (wh(l) == wh(r)) {
        push(wh(l));
        for (int i = l; i <= r; ++i) b[z][i] ^= f(c[i]++);
        build(wh(l));
        return;
    }
    int L = wh(l), R = wh(r);
    push(L), push(R);
    for (int i = l; i <= L * B; ++i) b[z][i] ^= f(c[i]++);
    for (int i = (R - 1) * B + 1; i <= r; ++i) b[z][i] ^= f(c[i]++);
    build(L), build(R);
    for (int i = L + 1; i <= R - 1; ++i) opt(z, i);
}

int query(int z, int l, int r) {
    int res = 0;
    if (wh(l) == wh(r)) {
        push(wh(l));
        for (int i = l; i <= r; ++i) res ^= b[z][i];
        build(wh(l));
        return res;
    }
    int L = wh(l), R = wh(r);
    push(L), push(R);
    for (int i = l; i <= L * B; ++i) res ^= b[z][i];
    for (int i = (R - 1) * B + 1; i <= r; ++i) res ^= b[z][i];
    build(L), build(R);
    for (int i = L + 1; i <= R - 1; ++i) res ^= sum[z][i];
    return res;
}

int a[N], pre[N], lst[N], res[N];
vector< pair<int, int> > qr[N];

signed main() {
    for (int i = 1; i < B; ++i) {
        tr[i] = (tr[i >> 1] >> 1) | ((i & 1) ? B >> 1 : 0);
        if (i != 1) _lg[i] = _lg[i >> 1] + 1;
    }
    int q; scanf("%d%d", &n, &q);
    for (int i = 1; i <= n; ++i) {
        scanf("%d", &a[i]);
        lst[i] = pre[a[i]] + 1;
        pre[a[i]] = i;
    }
    for (int i = 1, l, r; i <= q; ++i) {
        scanf("%d%d", &l, &r);
        qr[r].push_back({i, l});
    }
    for (int i = 1; i <= n; ++i) {
        modify(i & 1, lst[i], i);
        for (auto [x, y] : qr[i]) res[x] = query(i & 1, y, i);
    }
    for (int i = 1; i <= q; ++i) printf("%d\n", res[i]);
    return 0;
}