#include <bits/stdc++.h>
#pragma GCC target( "avx2" )
#pragma GCC optimize( "O3,unroll-loops" )

using namespace std;

const int NMAX = 1e5 + 10;

int v[NMAX];

int qry( int start, int finish ) {
    int x = 0;
    for ( int i = start; i <= finish; i ++ ) {
        x = max( x, v[i] );
        //x -= ((x - v[i]) & ((x - v[i]) >> 31));
    }
    return x;
}

vector <int> edges[NMAX + 1];
int subsize[NMAX + 1];
int father[NMAX + 1];
int root[NMAX + 1];
int depth[NMAX + 1];

int dfs( int node, int p = 0 ) {
    subsize[node] = 1;
    father[node] = p;
    depth[node] = depth[p] + 1;
    for ( auto vec : edges[node] ) {
        if ( vec != p ) {
            subsize[node] += dfs( vec, node );
        }
    }
    return subsize[node];
}

int poz[NMAX + 1], t = 0;

void calcHeavy( int node, int r ) {
    root[node] = r;
    poz[node] = t++;
    int hc = 0, sub = 0;
    for ( auto vec : edges[node] ) {
        if ( vec != father[node] && subsize[vec] > sub ) {
            sub = subsize[vec];
            hc = vec;
        }
    }
    if ( !hc ) return;
    calcHeavy( hc, r );
    for ( auto vec : edges[node] ) {
        if ( vec != hc && vec != father[node] ) {
            calcHeavy( vec, vec );
        }
    }
}

int query( int node, int anc ) {
    int ans = 0;
    for ( ; poz[anc] <= poz[node]; node = father[root[node]] ) {
        int start = max( poz[anc], poz[root[node]] );
        ans = max( ans, qry( start, poz[node] ) );
    }
    return ans;
}
int lca( int u, int v ) {
    if ( root[u] == root[v] ) {
        if ( depth[u] < depth[v] ) return u;
        return v;
    }
    if ( depth[root[u]] < depth[root[v]] ) return lca( u, father[root[v]] );
    return lca( father[root[u]], v );
}
int queryAll( int a, int b ) {
    int l = lca( a, b );
    return max( { query( a, l ), query( b, l ), v[poz[l]] } );
}
int a[NMAX + 1];

int main() {
    ifstream fin( "heavypath.in" );
    ofstream fout( "heavypath.out" );
    int n, q;
    fin >> n >> q;
    for ( int i = 1; i <= n; i ++ ) fin >> a[i];
    for ( int i = 1, a, b; i < n; i ++ ) {
        fin >> a >> b;
        edges[a].push_back( b );
        edges[b].push_back( a );
    }
    dfs( 1 );
    calcHeavy( 1, 1 );
    poz[0] = -1;
    for ( int i = 1; i <= n; i ++ ) v[poz[i]] = a[i];
    
    for ( int i = 1, a, b, x; i <= q; i ++ ) {
        string s;
        fin >> s >> a >> b;
        if ( s == "1" ) {
            fout << queryAll( a, b ) << '\n';
        } else {
            v[poz[a]] = b;
        }
    }
    
    return 0;
}