#include <algorithm>
#include <cstdio>
using namespace std;
const int TMAX = 400500;
const int NMAX = 100050;

int mx,pom[TMAX],v[NMAX];

void update(int nod, int st, int dr, int val){
    if(st==dr){
        pom[nod]=v[val];
        return;
    }
    int m=(st+dr)/2;
    if(val>m)   update(nod*2+1, m+1, dr, val);
    else        update(nod*2,    st, m, val);

    pom[nod] = max(pom[2*nod], pom[2*nod+1]);
}
void query(int nod, int st, int dr, int a, int b){
    if(a<=st && dr<=b){
        mx=max(mx, pom[nod]);
        return;
    }
    int m=(st+dr)/2;
    if(a<=m) query(2*nod, st, m, a, b);
    if(b>m) query(2*nod+1, m+1, dr, a, b);
}

int main(void){
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    int i,j,t,a,b,n,m;
    scanf("%d%d",&n,&m);
    for(i=1; i<=n; ++i)
        scanf("%d",&v[i]);
    for(i=1; i<=n; ++i)
        update(1,1,n,i);
    for(i=1; i<=m; ++i){
        scanf("%d",&t);
        if(t){
            scanf("%d%d",&a,&b);
            v[a]=b;
            update(1, 1, n, a);
        }
        else{
            mx=-1;
            scanf("%d%d",&a,&b);
            query(1,1,n,a,b);
            printf("%d\n",mx);
        }
    }
    return 0;
}