#include<cstdio>
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);}
return 0;}