/* Time complexity: O (N * sqrt(N)) */

#define _CRT_SECURE_NO_DEPRECATE
#include <stdio.h>
#include <ctime>
#define in "arbint.in"
#define out "arbint.out"
#define dim 100000

int max(int a, int b) {
	return a > b ? a : b;
}

int N, M, X, Y, size;
int T[dim], A[dim], L[dim], R[dim];

void Update(){
	A[--X] = Y;
	for (int i = 0; i <= size; ++i)
		if (X >= L[i]){
			T[i] = -1;
			for (int j = L[i]; j <= R[i]; ++j)
				T[i] = max(T[i], A[j]);
			break;
		}
}

int Query() {
	--X, --Y;
	int Max = -1, l = (X + size - 1) / size, r = (Y - size + 1) / size, i;
	if ((Y - size + 1) < 0) r = -1;

	for (i = l; i <= r; ++i) Max = max(Max, T[i]);
	for (i = X; i % size && i <= Y; ++i) Max = max(Max, A[i]);
	for (i = Y; (i + 1) % size && i >= X; --i)Max = max(Max, A[i]);

	return Max;
}

float t;

int main(){
	freopen(in, "r", stdin);
	freopen(out, "w", stdout);

	scanf("%d %d", &N, &M);
	for (size = 1; size * size <= N; ++size);
	--size;
	for (int i = 0; i < N; ++i)
		scanf("%d", &A[i]),
		T[i / size] = max(T[i / size], A[i]);

	for (int i = 0; i <= size; ++i)
		L[i] = i * size, R[i] = (i + 1) * size - 1;

	for (int type; M; --M){
		scanf("%d %d %d", &type, &X, &Y);
		if (type) Update();
		else printf("%d\n", Query());
	}
	t = (float)clock() / CLOCKS_PER_SEC;
	return 0;
}