#include <fstream>
using namespace std;
int v[100010], A[400010];
int n, m, i, a, b, tip, sol;

inline int maxim (int a, int b) {
    if (a > b)
        return a;
    else
        return b;
}

void build(int nod, int st, int dr) {
    if (st == dr)
        A[nod] = v[st];
    else {
        int mid = (st+dr)/2;
        build(2*nod, st, mid);
        build(2*nod+1, mid+1, dr);
        A[nod] = maxim(A[2*nod], A[2*nod+1]);
    }
}

void update(int nod, int st, int dr, int poz, int valoare) {
    if (st == dr) {
        A[nod] = valoare;
    } else {
        int mid = (st + dr)/2;
        if (poz <= mid)
            update(2*nod, st, mid, poz, valoare);
        else
            update(2*nod+1, mid+1, dr, poz, valoare);
        A[nod] = maxim(A[2*nod], A[2*nod+1]);
    }
}

void query(int nod,int st, int dr, int a, int b) {
    if (a <= st && dr <= b) {
        sol = maxim(sol, A[nod]);
    } else {
        int mid = (st+dr)/2;
        if (a <= mid)
            query(2*nod, st, mid, a, b);
        if (b >= mid+1)
            query(2*nod+1, mid+1, dr, a, b);
    }
}

int main () {
    ifstream fin("arbint.in");
    ofstream fout("arbint.out");

    fin>>n>>m;
    for (i=1;i<=n;i++) {
        fin>>v[i];
        /// ori fac un build si il apelez apoi
        /// ori update(1, 1, n, i, v[i])
    }
    build(1, 1, n);
    for (i=1;i<=m;i++) {
        fin>>tip>>a>>b;
        if (tip == 0) {
            sol =0;
            query(1, 1, n, a, b);
            fout<<sol<<"\n";
        } else {
            update(1, 1, n, a, b); /// v[a] = b;
        }
    }
    return 0;
}