// generated by GPT 5 pro
// LLMの作問能力評価のために自動生成された回答
// by CPCTF 運営チーム

#include <bits/stdc++.h>
using namespace std;

struct Node {
    long long mx1, mx2; // top1, top2
    Node(long long a = LLONG_MIN/4, long long b = LLONG_MIN/4) : mx1(a), mx2(b) {}
};

struct SegTree {
    int n; // size of base array (N-1)
    vector<Node> st;
    SegTree() : n(0) {}
    SegTree(const vector<long long>& base) { build(base); }

    static Node mergeNode(const Node& L, const Node& R) {
        Node res;
        if (L.mx1 >= R.mx1) {
            res.mx1 = L.mx1;
            res.mx2 = max({L.mx2, R.mx1, R.mx2});
        } else {
            res.mx1 = R.mx1;
            res.mx2 = max({R.mx2, L.mx1, L.mx2});
        }
        return res;
    }

    void build(const vector<long long>& base) {
        n = (int)base.size();
        if (n == 0) {
            st.clear();
            return;
        }
        st.assign(4*n, Node());
        build(1, 0, n-1, base);
    }
    void build(int p, int l, int r, const vector<long long>& base) {
        if (l == r) {
            st[p] = Node(base[l], LLONG_MIN/4);
            return;
        }
        int m = (l + r) >> 1;
        build(p<<1, l, m, base);
        build(p<<1|1, m+1, r, base);
        st[p] = mergeNode(st[p<<1], st[p<<1|1]);
    }

    void update(int idx, long long val) {
        if (n == 0) return;
        if (idx < 0 || idx >= n) return;
        update(1, 0, n-1, idx, val);
    }
    void update(int p, int l, int r, int idx, long long val) {
        if (l == r) {
            st[p] = Node(val, LLONG_MIN/4);
            return;
        }
        int m = (l + r) >> 1;
        if (idx <= m) update(p<<1, l, m, idx, val);
        else update(p<<1|1, m+1, r, idx, val);
        st[p] = mergeNode(st[p<<1], st[p<<1|1]);
    }

    Node query(int L, int R) {
        if (n == 0) return Node();
        if (L > R) return Node();
        L = max(L, 0);
        R = min(R, n-1);
        if (L > R) return Node();
        return query(1, 0, n-1, L, R);
    }
    Node query(int p, int l, int r, int L, int R) {
        if (R < l || r < L) return Node();
        if (L <= l && r <= R) return st[p];
        int m = (l + r) >> 1;
        Node left = query(p<<1, l, m, L, R);
        Node right = query(p<<1|1, m+1, r, L, R);
        return mergeNode(left, right);
    }
};

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int N, Q;
    if (!(cin >> N >> Q)) return 0;
    vector<long long> A(N+1);
    for (int i = 1; i <= N; ++i) cin >> A[i];

    // Build M[i] = min(A[i], A[i+1]) for i=1..N-1 -> 0-based index i-1
    vector<long long> M;
    if (N >= 2) {
        M.resize(N-1);
        for (int i = 1; i <= N-1; ++i) M[i-1] = min(A[i], A[i+1]);
    }
    SegTree seg(M);

    auto second_largest_of4 = [](long long a, long long b, long long c, long long d) -> long long {
        long long b1 = LLONG_MIN/4, b2 = LLONG_MIN/4;
        long long arr[4] = {a, b, c, d};
        for (int i = 0; i < 4; ++i) {
            long long x = arr[i];
            if (x > b1) {
                b2 = b1;
                b1 = x;
            } else if (x > b2) {
                b2 = x;
            }
        }
        return b2;
    };

    while (Q--) {
        int t; cin >> t;
        if (t == 1) {
            int i; long long x;
            cin >> i >> x;
            A[i] = x;
            if (N >= 2) {
                if (i > 1) {
                    seg.update(i-2, min(A[i-1], A[i]));
                }
                if (i < N) {
                    seg.update(i-1, min(A[i], A[i+1]));
                }
            }
        } else {
            int l, r; cin >> l >> r;
            Node res = seg.query(l-1, r-2); // M indices from l..r-1 -> 0-based [l-1, r-2]
            long long ans = second_largest_of4(A[l], A[r], res.mx1, res.mx2);
            cout << ans << '\n';
        }
    }
    return 0;
}