#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
struct Node{
    int left,right;
    int s;
}a[800010];
void built(int cur,int x,int y){
    a[cur].left=x; a[cur].right=y;
    if(x==y){
        scanf("%d",&a[cur].s);
        return ;
    }
    int mid=(x+y)>>1;
    built(cur<<1,x,mid);
    built(cur<<1|1,mid+1,y);
    a[cur].s=max(a[cur<<1].s,a[cur<<1|1].s);
}
void insert(int cur,int v,int val){
    if(a[cur].left==v && a[cur].right==v){
        a[cur].s=val;
        return ;
    }
    int mid=(a[cur].left+a[cur].right)>>1;
    if(v<=mid)
        insert(cur<<1,v,val);
    else
        insert(cur<<1|1,v,val);
    a[cur].s=max(a[cur<<1].s,a[cur<<1|1].s);
}
int query(int cur,int x,int y){
    if(a[cur].left==x && a[cur].right==y){
        return a[cur].s;
    }
    int mid=(a[cur].left+a[cur].right)>>1;
    if(y<=mid)
        return query(cur<<1,x,y);
    else if(x>mid)
        return query(cur<<1|1,x,y);
    else
        return max(query(cur<<1,x,mid),query(cur<<1|1,mid+1,y));
}
void output(int cur){
    if(a[cur].left==a[cur].right){
        cout<<a[cur].s<<' ';
        return ;
    }
    output(cur<<1);
    output(cur<<1|1);
}
int main(){
    int n,m;
    while(scanf("%d%d",&n,&m)!=EOF){
        built(1,1,n);
        //output(1);
        //printf("%d %d %d\n",a[1].s,a[1].left,a[1].right);
        while(m--){
            char ch[2];
            scanf("%s",&ch);
            if(ch[0]=='Q'){
                int x,y; scanf("%d%d",&x,&y);
                cout<<query(1,x,y)<<endl;
            }
            else{
                int v,val; scanf("%d%d",&v,&val);
                insert(1,v,val);
            }
        }
    }
    return 0;
}