// hdu 1754 I Hate It 线段树 点改动

//

// 不多说，裸的点改动

//

// 继续练

#include <algorithm>

#include <bitset>

#include <cassert>

#include <cctype>

#include <cfloat>

#include <climits>

#include <cmath>

#include <complex>

#include <cstdio>

#include <cstdlib>

#include <cstring>

#include <ctime>

#include <deque>

#include <functional>

#include <iostream>

#include <list>

#include <map>

#include <numeric>

#include <queue>

#include <set>

#include <stack>

#include <vector>

#define ceil(a,b) (((a)+(b)-1)/(b))

#define endl '\n'

#define gcd __gcd

#define highBit(x) (1ULL<<(63-__builtin_clzll(x)))

#define popCount __builtin_popcountll

typedef long long ll;

using namespace std;

const int MOD = 1000000007;

const long double PI = acos(-1.L);

template<class T> inline T lcm(const T& a, const T& b) { return a/gcd(a, b)*b; }

template<class T> inline T lowBit(const T& x) { return x&-x; }

template<class T> inline T maximize(T& a, const T& b) { return a=a<b?b:a; }

template<class T> inline T minimize(T& a, const T& b) { return a=a<b?a:b; }

const int maxn = 8 * 1e5 +8;

int maxv[maxn];

int n,m;

const int inf = 0x7f7f7f7f;

void build(int root,int L,int R){

	if (L==R){

		scanf("%d",&maxv[root]);

		return ;

	}

	int M = L + ( R - L ) / 2;

	build(root*2,L,M);

	build(root*2+1,M+1,R);

	maxv[root] = max(maxv[root*2],maxv[root*2+1]);

}

int p,v;

void update(int root,int L,int R){

	if (L==R){

		maxv[root] = v;

		return ;

	}

	int M = L + ( R - L ) / 2;

	if (p<=M)	update(root*2,L,M);

	else update(root*2+1,M+1,R);

	maxv[root] = max(maxv[root*2],maxv[root*2+1]);

}

int query(int root,int ql,int qr,int L,int R){

	if (ql<=L && R<=qr){

		return maxv[root];

	}

	int M = L + ( R - L) / 2;

	int ans = 0;

	if (ql<=M)	ans = max(ans,query(root*2,ql,qr,L,M));

	if (M<qr)	ans = max(ans,query(root*2+1,ql,qr,M+1,R));

	return ans;

}

void init(){

	build(1,1,n);

	char s[3];

	for (int i=0;i<m;i++){

		int x,y;

		scanf("%s%d%d",s,&x,&y);

		if (s[0]=='Q'){

			printf("%d\n",query(1,x,y,1,n));

		}else {

			p = x;

			v = y;

			update(1,1,n);

		}

	}

}

int main() {

//	freopen("G:\\Code\\1.txt","r",stdin);

	while(scanf("%d%d",&n,&m)!=EOF){

		init();

	}

	return 0;

}