#include <fstream>
#include <vector>
using std::vector;

unsigned read(std::istream &in,vector<unsigned> &tree, unsigned node, unsigned cleft, unsigned cright){
    if(cleft==cright){
        in>>tree[node];
        return tree[node];
    }
    else{
        unsigned mid = (cleft+cright)>>1;
        tree[node] = read(in,tree,node<<1,cleft,mid);
        unsigned right = read(in,tree,(node<<1)+1,mid+1,cright);
        if(right>tree[node]) tree[node]=right;
        return tree[node];
    }
}

unsigned alter(unsigned pos, unsigned val, vector<unsigned> &tree, unsigned node, unsigned cleft, unsigned cright){
    // !!! cleft<=pos and pos<=cright
    if(cleft==cright) return tree[node]=val;
    else{
        unsigned mid = (cleft+cright)>>1;
        if(pos<=mid){
            tree[node]=tree[(node<<1)+1];
            unsigned left = alter(pos,val,tree,node<<1,cleft,mid);
            if(left>tree[node]) tree[node]=left;
        }
        else{
            tree[node]=tree[node<<1];
            unsigned right = alter(pos,val,tree,(node<<1)+1,mid+1,cright);
            if(right>tree[node]) tree[node]=right;
        }
        return tree[node];
    }
}
unsigned getmax(const unsigned a,const unsigned b,const vector<unsigned> &tree,const unsigned node,const unsigned cleft,const unsigned cright){
    // !!! cleft <= a <= b <= cright
    if(cleft==cright) return tree[node];
    else{
        unsigned mid = (cleft+cright)>>1;
        if(b<=mid) return getmax(a,b,tree,node<<1,cleft,mid);
        else if(a<=mid){
            unsigned left=getmax(a,mid,tree,node<<1,cleft,mid);
            unsigned right=getmax(mid+1,b,tree,(node<<1)+1,mid+1,cright);
            if(left>right) return left;
            else return right;
        }
        else return getmax(a,b,tree,(node<<1)+1,mid+1,cright);
    }
}

int main(){
    std::ifstream fin("arbint.in");
    std::ofstream fout("arbint.out");

    unsigned N,M;
    fin>>N>>M;
    vector<unsigned> tree( ( (N&(N-1))==0 )?(N<<1):(N<<2) ,0);
    unsigned temp1,temp2;
    char c;

    read(fin,tree,1,1,N);

    while(M--){
        fin>>c>>temp1>>temp2;
        if(c=='0') fout<<getmax(temp1,temp2,tree,1,1,N)<<'\n';
        else alter(temp1,temp2,tree,1,1,N);
    }
}