//============================================================================// Name : HH.cpp// Author : lxw// Version :// Copyright : Your copyright notice// Description : Hello World in C++, Ansi-style//============================================================================#include <iostream>#include<algorithm>using namespace std;#define lson u<<1#define rson u<<1|1const int maxn=200010;int dat[maxn];struct Node{int lef,rig,score,Max;}T[maxn<<2];void Build(int u,int l,int r){T[u].lef=l;T[u].rig=r;if(l==r){T[u].Max=T[u].score=dat[l];return;}int mid=(l+r)>>1;Build(lson,l,mid);Build(rson,mid+1,r);T[u].Max=max(T[lson].Max,T[rson].Max);}void Update(int u,int index,int val){if(T[u].lef==index&&T[u].rig==index){T[u].Max=T[u].score=val;return;}else {if(index<=T[lson].rig)Update(lson,index,val);else Update(rson,index,val);T[u].Max=max(T[lson].Max,T[rson].Max);}}int Query(int u,int from,int to){if(T[u].lef==from&&T[u].rig==to){return T[u].Max;}if(to<=T[lson].rig)return Query(lson,from,to);if(from>=T[rson].lef)return Query(rson,from,to);return max(Query(lson,from,T[lson].rig),Query(rson,T[rson].lef,to));}int main() {int m,n;char cmd;int a,b;while(scanf("%d%d",&n,&m)==2){for(int i=1;i<=n;i++)scanf("%d",&dat[i]);Build(1,1,n);while(m--){scanf(" %c%d%d",&cmd,&a,&b);if(cmd=='U')Update(1,a,b);else {int ans=Query(1,a,b);printf("%d\n",ans);}}}return 0;}
