1 #include<iostream>
  2 #include<cstdio>
  3 #include<cstdlib>
  4 #include<cstring>
  5 #include<algorithm>
  6 #include<map>
  7 
  8 #define For(i,a,b)for(register int i=a;i<=b;++i)
  9 #define Dwn(i,a,b)for(register int i=a;i>=b;--i)
 10 #define
 
 Re register
 11 #define Pn putchar('\n')
 12 
 13 using namespace std;
 14 
 15 const int N=1e5+5,Nr=1e7+5;
 16 int head[N],nxt[N*2],v[N*2],cnt=1;
 17 int f[N][21],dfx[N],dID=0,dep[N],sz[N];
 18 int rt[N*3],ls[Nr],rs[Nr],tag[Nr],tr[Nr],tID=0;
 19 int n,m,x,y,T[N*3],cID=0,t,Q,ans=0;
 20 map<int
 
,int>mp;
 21 inline void read(int &v){
 22     v=0;
 23     char c=getchar();
 24     while(c<'0'||c>'9')c=getchar();
 25     while(c>='0'&&c<='9')v=v*10+c-'0',c=getchar();
 26 }
 27 void write(int x){
 28     if(x>9)write(x/10);
 29     int xx=x%10;
 30     putchar(xx+'
 
0');
 31 }
 32 void add(int ux,int vx){
 33     cnt++;
 34     nxt[cnt]=head[ux]; head[ux]=cnt; v[cnt]=vx;
 35     cnt++;
 36     nxt[cnt]=head[vx]; head[vx]=cnt; v[cnt]=ux;
 37 }
 38 
 39 void DFS(int x,int fa){
 40     sz[x]=1;
 41     dfx[x]=++dID;
 42     for(Re int i=head[x];i;i=nxt[i]){
 43         int vv=v[i];
 44         if(vv==fa)continue;
 45         dep[vv]=dep[x]+1;
 46         f[vv][0]=x;
 47         DFS(vv,x);
 48         sz[x]+=sz[vv];
 49     }
 50 }
 51 
 52 int LCA(int x,int y){
 53     if(dep[x]<dep[y])swap(x,y);
 54     Dwn(b,20,0)if(f[x][b]!=-1){
 55         if(dep[f[x][b]]>=dep[y])x=f[x][b];
 56     }
 57     if(x==y)return x;
 58     Dwn(b,20,0)if(f[x][b]!=-1&&f[y][b]!=-1&&f[x][b]!=f[y][b]){
 59         x=f[x][b]; y=f[y][b];
 60     }
 61     return f[x][0];
 62 }
 63 
 64 
 65 void pDown(int o,int l,int r){
 66     if(!tag[o]||l==r)return;
 67     int tg=tag[o]; tag[o]=0;
 68     if(!ls[o])ls[o]=++tID;
 69     if(!rs[o])rs[o]=++tID;
 70     tr[ls[o]]+=tg; tag[ls[o]]+=tg;
 71     tr[rs[o]]+=tg; tag[rs[o]]+=tg;
 72 }
 73 
 74 void Ins(int &o,int l,int r,int lx,int rx,int dt){
 75     if(!o)o=++tID;
 76     if(lx<=l&&rx>=r){
 77         tr[o]+=dt; tag[o]+=dt;
 78         return;
 79     }
 80     pDown(o,l,r);
 81     int m=(l+r)>>1;
 82     if(lx<=m)Ins(ls[o],l,m,lx,rx,dt);
 83     if(rx>m)Ins(rs[o],m+1,r,lx,rx,dt);
 84 }
 85 
 86 int Qry(int o,int l,int r,int px){
 87     if(!o)return 0;
 88     if(l==r)return tr[o];
 89     pDown(o,l,r);
 90     int m=(l+r)>>1;
 91     if(px<=m)return Qry(ls[o],l,m,px);
 92     else return Qry(rs[o],m+1,r,px);
 93 }
 94 
 95 
 96 int main(){
 97     freopen("garden.in","r",stdin);
 98     freopen("garden.out","w",stdout);
 99     read(n); read(Q);
100     For(i,1,n){
101         read(t);
102         if(!mp[t])mp[t]=++cID;
103         T[i]=mp[t];
104     }
105     For(i,1,n-1){
106         read(x); read(y);
107         add(x,y);
108     }
109     
110     memset(f,-1,sizeof(f));
111     DFS(1,0);
112     For(b,1,20) For(i,1,n){
113         if(f[i][b-1]==-1)continue;
114         f[i][b]=f[ f[i][b-1] ][b-1];
115     }
116     
117     For(i,1,n){
118         int lx=dfx[i];
119         int rx=dfx[i]+sz[i]-1;
120         Ins(rt[T[i]],1,n,lx,rx,1);
121     }
122     
123     For(i,1,Q){
124         
125         char opt=getchar();
126         while(opt!='C'&&opt!='Q')opt=getchar();
127         if(opt=='C'){
128             read(x); read(t);
129             x^=ans; t^=ans;
130             if(!mp[t])mp[t]=++cID;
131             t=mp[t];
132             int lx=dfx[x],rx=dfx[x]+sz[x]-1;
133             
134             Ins(rt[T[x]],1,n,lx,rx,-1);
135             Ins(rt[t],1,n,lx,rx,1);
136             T[x]=t;
137         }
138         if(opt=='Q'){
139             read(x); read(y); read(t);
140             x^=ans; y^=ans; t^=ans;
141             if(!mp[t])mp[t]=++cID;
142             t=mp[t];
143             int xy=LCA(x,y);
144             int fn;
145             fn=Qry(rt[t],1,n,dfx[x])+Qry(rt[t],1,n,dfx[y]);
146             fn-=Qry(rt[t],1,n,dfx[xy])*2;
147             if(T[xy]==t)fn++;
148             ans=fn;
149             write(fn); Pn;
150         }
151     }
152     fclose(stdin); fclose(stdout);
153     return 0;
154 }