#include<iostream>
#include<cstdio>
#include<cstring>
#define MAXN 100005
#define RG register
using namespace std;
int n,m,head[MAXN],cnt=0,ans,col[MAXN];
int sz=0,pos[MAXN],top[MAXN],dep[MAXN],son[MAXN],father[MAXN],siz[MAXN],inv[MAXN];
inline int read()
{
int f=1,x=0;char c=getchar();
while(c<'0'||x>'9'){if(c=='-')f=-1;c=getchar();}
while(c>='0'&&c<='9'){x=x*10+c-'0';c=getchar();}
return f*x;
}
struct Node1{
int next,to;
}Edges[MAXN*2];
inline void addedge(int u,int v)
{
Edges[++cnt].next=head[u];
head[u]=cnt;
Edges[cnt].to=v;
}
inline void dfs1(int u)
{
siz[u]=1;
for(int i=head[u];~i;i=Edges[i].next)
{
int v=Edges[i].to;
if(v==father[u])continue;
father[v]=u;dep[v]=dep[u]+1;
dfs1(v);siz[u]+=siz[v];
if(siz[v]>siz[son[u]])son[u]=v;
}
}
inline void dfs2(int u,int t)
{
sz++,pos[u]=sz;
inv[sz]=u,top[u]=t;
if(son[u])dfs2(son[u],t);
for(int i=head[u];~i;i=Edges[i].next)
{
int v=Edges[i].to;
if(v==father[u]||v==son[u])continue;
dfs2(v,v);
}
}
struct Node2{
int lc,rc,num,lazy;
}t[MAXN*3];
inline void pushdown(int idx,int l,int r)
{
if(l!=r&&t[idx].lazy)
{
t[idx<<1].lazy=t[idx<<1|1].lazy=t[idx<<1].num=t[idx<<1|1].num=1;
t[idx].lazy=0;
t[idx<<1].lc=t[idx<<1|1].lc=t[idx<<1].rc=t[idx<<1|1].rc=t[idx].lc;
}
}
inline void update(int idx)
{
t[idx].lc=t[idx<<1].lc;
t[idx].rc=t[idx<<1|1].rc;
t[idx].num=t[idx<<1].num+t[idx<<1|1].num-(t[idx<<1].rc==t[idx<<1|1].lc);
}
inline void build(int idx,int l,int r)
{
t[idx].lazy=0;
if(l==r)
{
t[idx].lc=t[idx].rc=col[inv[l]];
t[idx].num=1;
return;
}
int mid=(l+r)>>1;
build(idx<<1,l,mid),build(idx<<1|1,mid+1,r);
update(idx);
}
inline void color(int idx,int l,int r,int a,int b,int c)
{
if(l==a&&r==b)
{
t[idx].num=t[idx].lazy=1;
t[idx].lc=t[idx].rc=c;
return;
}
pushdown(idx,l,r);
int mid=(l+r)>>1;
if(a>mid)color(idx<<1|1,mid+1,r,a,b,c);
else if(b<=mid)color(idx<<1,l,mid,a,b,c);
else
{
color(idx<<1|1,mid+1,r,mid+1,b,c);
color(idx<<1,l,mid,a,mid,c);
}
update(idx);
}
inline int query(int idx,int l,int r,int a,int b)
{
if((l==a&&r==b)||t[idx].lazy)return t[idx].num;
pushdown(idx,l,r);
int mid=(l+r)>>1,ans=0;
if(a>mid)return query(idx<<1|1,mid+1,r,a,b);
else if(b<=mid)return query(idx<<1,l,mid,a,b);
else
{
ans+=query(idx<<1,l,mid,a,mid);
ans+=query(idx<<1|1,mid+1,r,mid+1,b);
ans-=t[idx<<1].rc==t[idx<<1|1].lc;
}
return ans;
}
inline int getcolor(int idx,int l,int r,int a)
{
if(l==r||t[idx].lazy)return t[idx].lc;
int mid=(l+r)>>1;
if(a<=mid)return getcolor(idx<<1,l,mid,a);
else return getcolor(idx<<1|1,mid+1,r,a);
}
inline void solve1(int x,int y,int z)
{
while(top[x]!=top[y])
{
if(dep[top[x]]<dep[top[y]])swap(x,y);
color(1,1,sz,pos[top[x]],pos[x],z);
x=father[top[x]];
}
if(pos[x]<pos[y])swap(x,y);
color(1,1,sz,pos[y],pos[x],z);
}
inline void solve2(int x,int y)
{
ans=0;
while(top[x]!=top[y])
{
if(dep[top[x]]<dep[top[y]])swap(x,y);
ans+=query(1,1,sz,pos[top[x]],pos[x]);
if(getcolor(1,1,sz,pos[top[x]])==getcolor(1,1,sz,pos[father[top[x]]]))ans--;
x=father[top[x]];
}
if(pos[x]<pos[y])swap(x,y);
ans+=query(1,1,sz,pos[y],pos[x]);
printf("%d\n",ans);
}
int main()
{
memset(head,-1,sizeof(head));
n=read(),m=read();
for(RG int i=1;i<=n;++i)col[i]=read();
int x,y,z;
for(RG int i=1;i<n;++i)
{
x=read(),y=read();
addedge(x,y),addedge(y,x);
}
dfs1(1),dfs2(1,1);
build(1,1,sz);
char opt;
for(RG int i=1;i<=m;++i)
{
opt=getchar();
while(opt!='C'&&opt!='Q')opt=getchar();
if(opt=='C')
x=read(),y=read(),z=read(),solve1(x,y,z);
else if(opt=='Q')
x=read(),y=read(),solve2(x,y);
}
return 0;
}
