#include<bits/stdc++.h>
using namespace std;
int s[100005],a[100005],b[100005],n,m,mmax=-1;
char q[100005];
int main(){
    cin>>n>>m;
   	for(int i=1;i<=n;i++)cin>>s[i];
   	for(int i=1;i<=m;i++){
	   	cin>>q[i]>>a[i]>>b[i];
   		if(q[i]=='Q'){
   			mmax=-1;
   			for(int j=a[i];j<=b[i];j++)mmax=max(mmax,s[j]);
   			cout<<mmax<<endl;
		}
		else{
			if(s[a[i]]>=b[i])s[a[i]]=b[i];
		}	
	}
}