D open 65

/*
┓┏┓┏┓┃
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┛┗┛┗┛┃
┓┏┓┏┓┃＼○／
┛┗┛┗┛┃ / /
┓┏┓┏┓┃ノ
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┛┗┛┗┛┃┃
      MIPTCLASSICMIPTCLASSICMIPTCLASSICMIPTCLASSICMIPTCLASSICMIPTCLASSIC
*/

// #define pragma

#ifdef pragma
#pragma GCC optimize("Ofast")
#pragma GCC optimize("no-stack-protector")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,tune=native")
#pragma GCC optimize("unroll-loops")
#pragma GCC diagnostic ignored "-Wunused-result"
#endif // pragma

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

#define ll long long
#define all(x) begin(x), end(x)
#define pb push_back
#define x first
#define y second
#define int long long
#define zero(two) memset(two, 0, sizeof(two))

using namespace std;
using namespace __gnu_pbds;


typedef vector<int> vi;
typedef vector<bool> vb;
typedef pair<int, int> pii;
typedef long double ld;
typedef vector<vi> matrix;
template<typename T>
using kawaii_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

const ld PI = atan2(0, -1);

void seriy() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    cout << fixed << setprecision(10);
    #if 1
        freopen("input", "r", stdin);
        freopen("output", "w", stdout);
    #endif
}

struct rrq {
    int t, l, r, id;
};

struct crq {
    int t, pos, val;
};

const int INF = 1e9 + 7;
const int MAXN = 1e6 + 100;

int k;
vi addpos;
matrix add;
vi a, ccc(MAXN);
int curpos = 0;
vector<crq> crqs;
int curl = 1, curr = 0, curt = 0;

bool cmp(rrq a, rrq b) {
    if(a.t / k != b.t / k) {
        return a.t < b.t;
    }
    else if(a.l / k != b.l / k) {
        return a.l < b.l;
    }
    return a.r < b.r;
}

void addLeft(int pos) {
    pos = a[pos];
    ccc[pos]++;
    if(pos == curpos) {
        while(ccc[curpos]) {
            curpos++;
        }
    }
}

void addRight(int pos) {
    addLeft(pos);
}

void delLeft(int pos) {
    pos = a[pos];
    ccc[pos]--;
    if(ccc[pos] == 0 && pos < curpos) {
        curpos = pos;
    }
}

void delRight(int pos) {
    delLeft(pos);
}

void addT(int num) {
    int pos = crqs[num].pos;
    int val = crqs[num].val;
    if(pos >= curl && pos <= curr) {
        delLeft(pos);
    }
    addpos[pos]++;
    a[pos] = val;
    if(pos >= curl && pos <= curr) {
        addLeft(pos);
    }
}

void delT(int num) {
    int pos = crqs[num].pos;
    if(pos >= curl && pos <= curr) {
        delLeft(pos);
    }
    addpos[pos]--;
    a[pos] = add[pos][addpos[pos]];
    if(pos >= curl && pos <= curr) {
        addLeft(pos);
    }
}

int answer() {
    return curpos;
}

signed main() {
    seriy();
    int n, q;
    cin >> n >> q;
    a.resize(n);
    add.resize(n);
    addpos.resize(n, 0);
    int mxx = 0;
    for(int i = 0; i < n; i++) {
        cin >> a[i];
        mxx = max(mxx, a[i]);
        add[i].pb(a[i]);
    }
    vi l(q), r(q);
    int tt = 0;
    vector<rrq> rqs;
    vector<char> rq;
    for(int i = 0; i < q; i++) {
        char rqq;
        cin >> rqq;
        cin >> l[i] >> r[i];

        rq.pb(rqq);
        if(rqq == '!') {
            crqs.pb({tt + 1, l[i] - 1, r[i]});

            add[l[i] - 1].pb(r[i]);
//            cerr << l[i] << " " << r[i] << '\n';
            tt++;
        }
        else {
            l[i]--;
            r[i]--;
            rqs.pb({tt, l[i], r[i], i});
        }
    }
    if(mxx <= 10) {
        int num = 0;
        vector<set<int>> vs(11);
        for(int i = 0; i < n; i++) {
            vs[a[i]].insert(i);
        }
        while(q--) {
            if(rq[num] == '?') {
                int ans = 11;
                for(int i = 0; i < 11; i++) {
                    // cerr << (vs[i].lower_bound(l[num]) == vs[i].end()) << '\n';
                    if(vs[i].lower_bound(l[num]) == vs[i].end() || (*vs[i].lower_bound(l[num])) > r[num]) {
                        ans = i;
                        break;
                    }
                }
                // cerr << '\n';
                cout << ans << '\n';
            }
            else {
                l[num]--;
                int ans = 0;
                for(int i = 0; i < 11; i++) {
                    if(vs[i].lower_bound(l[num]) != vs[i].end() && (*vs[i].lower_bound(l[num])) == l[num]) {
                        ans = i;
                        break;
                    }
                }
                vs[ans].erase(l[num]);
                vs[r[num]].insert(l[num]);
            }
            num++;
        }
    }
    else {
        int num = 0;
        k = pow(n, 2. / 3.);
        sort(all(rqs), cmp);
        vi ans(q, -1);
        for(int i = 0; i < rqs.size(); i++) {

            while(curt < rqs[i].t) {
                addT(curt);
                curt++;
            }
            while(curl > rqs[i].l) {
                curl--;
                addLeft(curl);
            }
            while(curr < rqs[i].r) {
                curr++;
                addRight(curr);
            }

            while(curl < rqs[i].l) {
                delLeft(curl);
                curl++;
            }
            while(curr > rqs[i].r) {
                delRight(curr);
                curr--;
            }
            while(curt > rqs[i].t) {
                curt--;
                delT(curt);
            }
    //        for(auto j : a) {
    //            cerr << j << " ";
    //        }
    //        cerr << '\n';
    //        cerr << rqs[i].t << " " << rqs[i].l << " " << rqs[i].r << " " << answer() << '\n';
            ans[rqs[i].id] = answer();
        }
        for(auto i : ans) {
            if(i != -1) cout << i << '\n';
        }
    }
    return 0;
}