#include<iostream>

#include<cstring>

#include<cstdio>

#include<algorithm>

#include<queue>

using namespace std;

typedef long long ll;

const int N=4e5+;

int n,q,tot,cnt,tim;

int head[N],dep[N],siz[N],wson[N],fa[N],top[N],dfn[N],rt[N<<],color[N];

int lx[N<<],rx[N<<],sum[N<<];

ll a[N],b[N<<];

struct EDGE

{

    int to,nxt;

}edge[N];

struct QUE

{

    int op;

    int x,y;

    ll v;

}t[N];

inline ll read()

{

    char ch=getchar();ll s=,f=;

    while (ch<''||ch>'') {if (ch=='-') f=-;ch=getchar();}

    while (ch>=''&&ch<='') {s=(s<<)+(s<<)+ch-'';ch=getchar();}

    return s*f;

}

void add(int u,int v)

{

    edge[++tot]=(EDGE){v,head[u]};

    head[u]=tot;

}

void dfs1(int x,int pre)

{

    dep[x]=dep[pre]+;siz[x]=;fa[x]=pre;

    for (int i=head[x];i;i=edge[i].nxt)

    {

        int y=edge[i].to;

        if (y==pre) continue;

        dfs1(y,x);

        siz[x]+=siz[y];

        if (!wson[x]||siz[wson[x]]<siz[y]) wson[x]=y;

    }

}

void dfs2(int x,int tp)

{

    top[x]=tp;dfn[x]=++tim;

    if (wson[x]) dfs2(wson[x],tp);

    for (int i=head[x];i;i=edge[i].nxt)

    {

        int y=edge[i].to;

        if (y==fa[x]||y==wson[x]) continue;

        dfs2(y,y);

    }

}

void upd(int o)

{

    sum[o]=sum[lx[o]]+sum[rx[o]];

}

void update(int &o,int l,int r,int pos,int x)

{

    if (!o) o=++cnt;

    if (l==r)

    {

        sum[o]+=x;

        return;

    }

    int mid=l+r>>;

    if (pos<=mid) update(lx[o],l,mid,pos,x);

    else update(rx[o],mid+,r,pos,x);

    upd(o);

}

void change(int x,int v)

{

    if (color[x])

    {

        update(rt[color[x]],,n,dfn[x],-);

    }

    color[x]=v;

    update(rt[v],,n,dfn[x],);

}

int query(int o,int l,int r,int x,int y)

{

    if (!o) return ;

    if (l>=x&&r<=y) return sum[o];

    int mid=l+r>>,re=;

    if (x<=mid) re+=query(lx[o],l,mid,x,y);

    if (y>mid) re+=query(rx[o],mid+,r,x,y);

    return re;

}

int query_path(int x,int y,int v)

{

    int res=;

    while (top[x]!=top[y])

    {

        if (dep[top[x]]<dep[top[y]]) swap(x,y);

        res+=query(rt[v],,n,dfn[top[x]],dfn[x]);

        x=fa[top[x]];

    }

    if (dep[x]<dep[y]) swap(x,y);

    res+=query(rt[v],,n,dfn[y],dfn[x]);

    return res;

}

int main()

{

    //freopen("tree.in","r",stdin);

    n=read();q=read();

    int len=;

    for (int i=;i<=n;i++) a[i]=read(),b[++len]=a[i];

    for (int i=;i<n;i++)

    {

        int u=read(),v=read();

        add(u,v);add(v,u);

    }

    dfs1(,);

    dfs2(,);

    char s[];

    for (int i=;i<=q;i++)

    {

        scanf("%s",s);

        if (s[]=='C')

        {

            t[i].op=;

            t[i].x=read();t[i].v=read();

        }

        if (s[]=='Q')

        {

            t[i].op=;

            t[i].x=read();t[i].y=read();t[i].v=read();

        }

        b[++len]=t[i].v;

    }

    sort(b+,b++len);

    len=unique(b+,b++len)-b-;

    for (int i=;i<=n;i++) a[i]=lower_bound(b+,b++len,a[i])-b;

    for (int i=;i<=q;i++) t[i].v=lower_bound(b+,b++len,t[i].v)-b;

    for (int i=;i<=n;i++) change(i,a[i]);

    for (int i=;i<=q;i++)

    {

        if (t[i].op==)

        {

            change(t[i].x,t[i].v);

        }

        if (t[i].op==)

        {

            printf("%d\n",query_path(t[i].x,t[i].y,t[i].v));

        }

    }

    return ;

}