#include<cstdio>
#include<algorithm>
#define INF 100001
#define MAXlen 262144

using namespace std;

int arb[4*INF+666],n,m,poz=0;
char buff[MAXlen],ind=0;

inline void read(int &nr)
{
    int x=0;
    while(buff[ind]<'0'||buff[ind]>'9')
    {
        ++ind;
        if(ind==MAXlen){poz+=ind;fseek(stdin,poz,SEEK_SET);fread(buff,1,MAXlen,stdin);ind=0;}
    }
    while(buff[ind]>='0'&&buff[ind]<='9')
    {
        x=x*10+buff[ind]-48;
        ++ind;
        if(ind==MAXlen){poz+=ind;fseek(stdin,poz,SEEK_SET);fread(buff,1,MAXlen,stdin);ind=0;}
    }
    nr=x;
}

int maxVal(int nod,int st,int dr,int a,int b)
{
    if(dr<a||st>b)return -1;
    if(a<=st&&dr<=b)return arb[nod];
    int m=(st+dr)/2;
    int v1=-1,v2=-1;
    if(a<=m)v1=maxVal(nod*2,st,m,a,b);
    if(b>m)v2=maxVal(nod*2+1,m+1,dr,a,b);
    return max(v1,v2);
}

void update(int nod,int st,int dr,int poz,int val)
{
    if(poz<st||poz>dr)return;
    if(st==dr){arb[nod]=val;return;}
    int m=(st+dr)>>1;
    if(poz<=m)update(nod*2,st,m,poz,val);
        else update(nod*2+1,m+1,dr,poz,val);

    arb[nod]=max(arb[nod*2],arb[nod*2+1]);
}

int main()
{
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    //fread(buff,1,MAXlen,stdin);
    //read(n),read(m);
    scanf("%d%d",&n,&m);
    for(int i=1;i<=n;++i)
    {
        int x;
        //read(x);
        scanf("%d",&x);
        update(1,1,n,i,x);
    }
    for(int i=0;i<m;++i)
    {
        int c,a,b;
        //read(c);read(a);read(b);
        scanf("%d%d%d",&c,&a,&b);
        if(c==0)printf("%d\n",maxVal(1,1,n,a,b));
        else update(1,1,n,a,b);
    }
    return 0;
}