#include<stdio.h>
int n,m,y,z,h[275005],x,r;
void A(int n,int s,int d) {
    if(y<=s&&d<=z) {
        r=r<h[n]?h[n]:r;
        return;
    }
    int m=(s+d)/2;
    if(y<=m)
        A(2*n,s,m);
    if(z>m)
        A(2*n+1,m+1,d);
}
void B(int n,int s,int d) {
    if(s==d) {
        h[n]=z;
        return;
    }
    int m=(s+d)/2;
    if(y<=m)
        B(2*n,s,m);
    else
        B(2*n+1,m+1,d);
    h[n]=h[2*n]<h[2*n+1]?h[2*n+1]:h[2*n];
}
int main() {
    freopen("arbint.in","r",stdin),freopen("arbint.out","w",stdout),scanf("%d%d",&n,&m);
    for(y=1;y<=n;y++)
        scanf("%d",&z),B(1,1,n);
    while(m--) {
        scanf("%d%d%d",&x,&y,&z);
        if(!x)
            r=-1,A(1,1,n),printf("%d\n",r);
        else
            B(1,1,n);
    }
}