#include <cstdio>#include <iostream>#include <algorithm>#define maxn 200001using namespace std;struct TreeNodeType {    int l,r,dis,lc,rc,flag,mid;};struct TreeNodeType tree[maxn<<2];struct EdgeType {    int to,next;};struct EdgeType edge[maxn<<1];int n,m,if_z,dis[maxn],flag[maxn],dis_[maxn];int size[maxn],head[maxn],deep[maxn],f[maxn];int cnt,tot,num,belong[maxn];char Cget;inline void read_int(int &now){    now=0,if_z=1,Cget=getchar();    while(Cget>‘9‘||Cget<‘0‘)    {        if(Cget==‘-‘) if_z=-1;        Cget=getchar();    }    while(Cget>=‘0‘&&Cget<=‘9‘)    {        now=now*10+Cget-‘0‘;        Cget=getchar();    }    now*=if_z;}inline void edge_add(int from,int to){    edge[++num].to=from,edge[num].next=head[to],head[to]=num;    edge[++num].to=to,edge[num].next=head[from],head[from]=num;}void search(int now,int fa){    int pos=cnt++;    deep[now]=deep[fa]+1,f[now]=fa;    for(int i=head[now];i;i=edge[i].next)    {        if(edge[i].to==fa) continue;        search(edge[i].to,now);    }    size[now]=cnt-pos;}void search_(int now,int chain){    belong[now]=chain,flag[now]=++cnt;    dis_[flag[now]]=dis[now];    int pos=0;    for(int i=head[now];i;i=edge[i].next)    {        if(edge[i].to==f[now]) continue;        if(size[edge[i].to]>size[pos]) pos=edge[i].to;    }    if(pos!=0) search_(pos,chain);    else return ;    for(int i=head[now];i;i=edge[i].next)    {        if(edge[i].to==f[now]||edge[i].to==pos) continue;        search_(edge[i].to,edge[i].to);    }}inline void tree_up(int now){    if(tree[now<<1].rc==tree[now<<1|1].lc)    {        tree[now].dis=tree[now<<1].dis+tree[now<<1|1].dis-1;    }    else    {        tree[now].dis=tree[now<<1].dis+tree[now<<1|1].dis;    }    tree[now].lc=tree[now<<1].lc,tree[now].rc=tree[now<<1|1].rc;}inline void tree_down(int now){    if(tree[now].l==tree[now].r) return ;    tree[now<<1].dis=1,tree[now<<1|1].dis=1;    tree[now<<1].lc=tree[now<<1].rc=tree[now].flag;    tree[now<<1|1].lc=tree[now<<1|1].rc=tree[now].flag;    tree[now<<1].flag=tree[now<<1|1].flag=tree[now].flag;    tree[now].flag=0;}void tree_build(int now,int l,int r){    tree[now].l=l,tree[now].r=r;    if(l==r)    {        tree[now].lc=dis_[++cnt];        tree[now].rc=tree[now].lc;        tree[now].dis=1;        return ;    }    tree[now].mid=(l+r)>>1;    tree_build(now<<1,l,tree[now].mid);    tree_build(now<<1|1,tree[now].mid+1,r);    tree_up(now);}void tree_change(int now,int l,int r,int x){    if(tree[now].l==l&&tree[now].r==r)    {        tree[now].dis=1,tree[now].flag=x;        tree[now].lc=tree[now].rc=x;        return ;    }    if(tree[now].flag) tree_down(now);    if(l>tree[now].mid) tree_change(now<<1|1,l,r,x);    else if(r<=tree[now].mid) tree_change(now<<1,l,r,x);    else    {        tree_change(now<<1,l,tree[now].mid,x);        tree_change(now<<1|1,tree[now].mid+1,r,x);    }    tree_up(now);}int tree_query(int now,int l,int r){    if(tree[now].l==l&&tree[now].r==r)    {        return tree[now].dis;    }    if(tree[now].flag) tree_down(now);    tree_up(now);    if(l>tree[now].mid) return tree_query(now<<1|1,l,r);    else if(r<=tree[now].mid) return tree_query(now<<1,l,r);    else    {        int ld=tree_query(now<<1,l,tree[now].mid);        int rd=tree_query(now<<1|1,tree[now].mid+1,r);        if(tree[now<<1].rc==tree[now<<1|1].lc) return ld+rd-1;        else return ld+rd;    }}int tree_query_color(int now,int to){    if(tree[now].l==tree[now].r&&tree[now].l==to)    {        return tree[now].lc;    }    if(tree[now].flag) tree_down(now);    tree_up(now);    if(to>tree[now].mid) return tree_query_color(now<<1|1,to);    else return tree_query_color(now<<1,to);}inline void solve_change(int x,int y,int z){    while(belong[x]!=belong[y])    {        if(deep[belong[x]]<deep[belong[y]]) swap(x,y);        tree_change(1,flag[belong[x]],flag[x],z);        x=f[belong[x]];    }    tree_change(1,min(flag[x],flag[y]),max(flag[x],flag[y]),z);}inline int solve_query(int x,int y){    int ans=0;    while(belong[x]!=belong[y])    {        if(deep[belong[x]]<deep[belong[y]]) swap(x,y);        ans+=tree_query(1,flag[belong[x]],flag[x]);        if(tree_query_color(1,flag[belong[x]])==tree_query_color(1,flag[f[belong[x]]])) ans--;        x=f[belong[x]];    }    ans+=tree_query(1,min(flag[x],flag[y]),max(flag[x],flag[y]));    return ans;}int main(){    read_int(n),read_int(m);    for(int i=1;i<=n;i++) read_int(dis[i]);    int from,to,pos;    for(int i=1;i<n;i++)    {        read_int(from),read_int(to);        edge_add(from,to);    }    search(1,0),cnt=0,search_(1,1),cnt=0,tree_build(1,1,n);    char type;    for(int i=1;i<=m;i++)    {        cin>>type;        if(type==‘C‘)        {            read_int(from),read_int(to),read_int(pos);            solve_change(from,to,pos);        }        else        {            read_int(from),read_int(to);            printf("%d\n",solve_query(from,to));        }    }    return 0;}