//Ilie Dumitru
#include<cstdio>
#include<algorithm>
const int NMAX=100005;

FILE* input=fopen("arbint.in", "r");
FILE* output=fopen("arbint.out", "w");

struct segTreeNode
{
	int x;
	friend segTreeNode operator+(segTreeNode a, segTreeNode b)
	{
		a.x=std::max(a.x, b.x);
		return a;
	}
};
struct segTree
{
	int N;
	segTreeNode v[NMAX<<2];

	void init(int _N, segTreeNode* _v)
	{
		N=_N;
		build(0, 0, N-1, _v);
	}

	void initDefault(int _N, segTreeNode& defaultVal)
	{
		N=_N;
		buildDefault(0, 0, N-1, defaultVal);
	}

	void build(int node, int l, int r, segTreeNode* _v)
	{
		if(l==r)
		{
			v[node]=_v[l];
		}
		else
		{
			const int mid=l+((r-l)>>1);
			build((node<<1)|1, l, mid, _v);
			build((node<<1)+2, mid+1, r, _v);
			v[node]=v[(node<<1)|1]+v[(node<<1)+2];
		}
	}

	void buildDefault(int node, int l, int r, segTreeNode& defVal)
	{
		if(l==r)
		{
			v[node]=defVal;
		}
		else
		{
			const int mid=l+((r-l)>>1);
			buildDefault((node<<1)|1, l, mid, defVal);
			buildDefault((node<<1)+2, mid+1, r, defVal);
			v[node]=v[(node<<1)|1]+v[(node<<1)+2];
		}
	}

	segTreeNode query(int l, int r) {return query(0, 0, N-1, l, r);}
	segTreeNode query(int node, int l, int r, int st, int dr)
	{
		if(st<=l && r<=dr)
			return v[node];
		const int mid=l+((r-l)>>1);
		if(dr<=mid)
			return query((node<<1)|1, l, mid, st, dr);
		if(mid<st)
			return query((node<<1)+2, mid+1, r, st, dr);
		return query((node<<1)|1, l, mid, st, dr)+query((node<<1)+2, mid+1, r, st, dr);
	}

	void update(int pos, segTreeNode& x) {update(0, 0, N-1, pos, x);}
	void update(int node, int l, int r, int pos, segTreeNode& x)
	{
		if(l==r)
			v[node]=x;
		else
		{
			const int mid=l+((r-l)>>1);
			if(pos<=mid)
				update((node<<1)|1, l, mid, pos, x);
			else
				update((node<<1)+2, mid+1, r, pos, x);
			v[node]=v[(node<<1)|1]+v[(node<<1)+2];
		}
	}
};

segTree S;
segTreeNode init[NMAX];

int main()
{
	FILE *f=fopen("arbint.in", "r");
	FILE *g=fopen("arbint.out", "w");
	int i, N, _, op, a, b;
	segTreeNode x;
	fscanf(f, "%d%d", &N, &_);
	for(i=0;i<N;++i)
		fscanf(f, "%d", &init[i].x);
	S.init(N, init);
	do
	{
		fscanf(f, "%d%d%d", &op, &a, &b);
		if(op==0)
			fprintf(g, "%d\n", S.query(a-1, b-1).x);
		else
		{
			x.x=b;
			S.update(a-1, x);
		}
	}while(--_);
	fclose(f);
	fclose(g);
	return 0;
}