#include <cstdio>
#include <algorithm>
using namespace std;
const int N=200005;
const int maxn = N*3;
int val[maxn],a[maxn];
int n,m,ql,qr,pos,value;

void build(int num,int l,int r)
{
    if(l==r)
    {
        val[num] = a[l];
        return ;
    }
    int mid = (l+r)/2;
    build(num*2,l,mid);
    build(num*2+1,mid+1,r);
    val[num] = max(val[num*2],val[num*2+1]);
}

int Findmax(int num,int l,int r)
{
    int mid=(l+r)/2;
    int ans = 0;
    if(ql<=l&&qr>=r)
    {
        return val[num];
    }
    else
    {
        if(mid>=ql)
            ans = max(ans,Findmax(num*2,l,mid));
        if(mid<qr)
            ans = max(ans,Findmax(num*2+1,mid+1,r));
    }
    return ans;
}

void updata(int num,int l,int r)
{
    if(l==r)
    {
        val[num] = value;
        return ;
    }
    int mid = (l+r)/2;
    if(mid>=pos)
    {
        updata(num*2,l,mid);
    }
    else
    {
        updata(num*2+1,mid+1,r);
    }
    val[num] = max(val[num*2],val[num*2+1]);
}
int main()
{
    while(scanf("%d %d",&n,&m)!=EOF)
    {
        for(int i=1;i<=n;i++)
        {
            scanf("%d",&a[i]);
        }
        build(1,1,n);
        int A,B;char c;
        for(int i=1;i<=m;i++)
        {
            getchar();
            scanf("%c %d %d",&c,&A,&B);
            if(c==‘Q‘)
            {
                ql = A;
                qr = B;
                printf("%d\n",Findmax(1,1,n));
            }
            else
            {
                pos = A;
                value = B;
                updata(1,1,n);
            }
        }
    }
}