#include <bits/stdc++.h>
using namespace std;
const int MaxN=100010;
vector<int> g[MaxN];
int niv[MaxN],size[MaxN],val[MaxN],nr_lanturi;
int lant[MaxN],poz_lant[MaxN],lant_size[MaxN],lant_tata[MaxN];
vector<int> arb[MaxN];
void dfs1(int nod,int tata,int lev)
{
size[nod]=1;
niv[nod]=lev;
for(auto fiu : g[nod])
if(fiu!=tata)
{
dfs1(fiu,nod,lev+1);
size[nod]+=size[fiu];
}
}
void dfs2(int nod,int tata,int l)
{
lant[nod]=l;
poz_lant[nod]=++lant_size[l];
int heavy=0;
for(auto fiu : g[nod])
if(fiu!=tata && size[fiu]>size[heavy]) heavy=fiu;
if(!heavy) return;
dfs2(heavy,nod,l);
for(auto fiu : g[nod])
if(fiu!=tata && fiu!=heavy)
{
lant_tata[++nr_lanturi]=nod;
dfs2(fiu,nod,nr_lanturi);
}
}
void arbint_update(int nod,int st,int dr,int poz,int val,vector<int> &arb)
{
if(st==dr) arb[nod]=val;
else
{
int mid=(st+dr)/2;
if(poz<=mid) arbint_update(nod*2,st,mid,poz,val,arb);
else arbint_update(nod*2+1,mid+1,dr,poz,val,arb);
arb[nod]=max(arb[nod*2],arb[nod*2+1]);
}
}
int arbint_query(int nod,int st,int dr,int left,int right,vector<int> &arb)
{
if(left<=st && dr<=right) return arb[nod];
else
{
int mid=(st+dr)/2,ret=0;
if(left<=mid) ret=max(ret,arbint_query(nod*2,st,mid,left,right,arb));
if(mid<right) ret=max(ret,arbint_query(nod*2+1,mid+1,dr,left,right,arb));
return ret;
}
}
int main()
{
freopen("heavypath.in", "r", stdin);
freopen("heavypath.out", "w", stdout);
int n,m,x,y,tip;
scanf("%d%d",&n,&m);
for(int i=1;i<=n;i++) scanf("%d",&val[i]);
for(int i=1;i<n;i++)
{
scanf("%d%d",&x,&y);
g[x].push_back(y);
g[y].push_back(x);
}
dfs1(1,0,1);
nr_lanturi++;
dfs2(1,0,nr_lanturi);
for(int i=1;i<=nr_lanturi;i++)
arb[i].resize(4*lant_size[i]);
for(int i=1;i<=n;i++)
arbint_update(1,1,lant_size[lant[i]],poz_lant[i],val[i],arb[lant[i]]);
for(int i=1;i<=m;i++)
{
scanf("%d%d%d",&tip,&x,&y);
if(tip==0) arbint_update(1,1,lant_size[lant[x]],poz_lant[x],y,arb[lant[x]]);
else
{
int ret=0;
while(lant[x]!=lant[y])
{
if(niv[lant_tata[lant[x]]]<niv[lant_tata[lant[y]]]) swap(x,y);
ret=max(ret,arbint_query(1,1,lant_size[lant[x]],1,poz_lant[x],arb[lant[x]]));
x=lant_tata[lant[x]];
}
if(poz_lant[x]>poz_lant[y]) swap(x,y);
ret=max(ret,arbint_query(1,1,lant_size[lant[x]],poz_lant[x],poz_lant[y],arb[lant[x]]));
printf("%d\n",ret);
}
}
return 0;
}