#include<cstdio>

#include<cstring>

#include<string>

#include<vector>

#include<algorithm>

using namespace std;

const int maxn=;

int N,M,C[maxn];

struct lct

{

    lct *fa,*son[];

    int rev,c,setc,lc,rc,sum;

};

struct LCT

{

    lct data[maxn];

    lct *null;

    void init(int Size=maxn-) //初始化

    {

        null=data; //null指向首元素

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

        {

            data[i].son[]=data[i].son[]=data[i].fa=null;

            data[i].rev=;

            data[i].c=data[i].lc=data[i].rc=C[i];

            data[i].setc=-;

            data[i].sum=;

        }

        null->c=null->lc=null->rc=-;

        null->sum=;

    }

    void push_rev(lct* x)

    {

        if(x==null) return;

        x->rev=!x->rev;

        swap(x->son[],x->son[]);

        swap(x->lc,x->rc);

    }

    void push_setc(lct* x,int setc)

    {

        if(x==null) return;

        x->c=setc;

        x->setc=setc;

        x->lc=setc;

        x->rc=setc;

        x->sum=;

    }

    void pushdown(lct* x)

    {

        if(x->setc!=-)

        {

            push_setc(x->son[],x->setc);

            push_setc(x->son[],x->setc);

            x->setc=-;

        }

        if(x->rev)

        {

            push_rev(x->son[]);

            push_rev(x->son[]);

            x->rev=;

        }

    }

    void pushup(lct* x)

    {

        if(x==null) return;

        x->sum=;

        if(x->son[]!=null)

        {

            x->sum+=x->son[]->sum;

            if(x->son[]->rc==x->c) x->sum--;

        }

        if(x->son[]!=null)

        {

            x->sum+=x->son[]->sum;

            if(x->son[]->lc==x->c) x->sum--;

        }

        x->lc=x->c;

        if(x->son[]!=null) x->lc=x->son[]->lc;

        x->rc=x->c;

        if(x->son[]!=null) x->rc=x->son[]->rc;

    }

    bool Same(lct* x,lct* &y) //判断x和x的父亲是否在同一树里

    {

        return (y=x->fa)!=null&&(y->son[]==x||y->son[]==x);

    }

    void Rotate(lct* x,int d) //翻转

    {

        lct* y=x->fa; //x的父亲

        y->son[d^]=x->son[d];

        if(x->son[d]!=null) x->son[d]->fa=y; //x的子节点的父亲指向y

        x->fa=y->fa;  //连接

        if(y->fa->son[]==y) x->fa->son[]=x;

        else if(y->fa->son[]==y) x->fa->son[]=x;

        x->son[d]=y;

        y->fa=x;

    }

    void Splay(lct* x)

    {

        pushdown(x); //清除标记

        lct* y;

        while(Same(x,y)) //没有到树的最顶点

        {

            pushdown(y);

            pushdown(x);

            Rotate(x,y->son[]==x); //翻转

            pushup(y);

            pushup(x);

        }

    }

    lct* Access(lct* u)  //打通路径,返回的是根

    {

        lct *v=null;

        for(;u!=null;u=u->fa)

        {

            Splay(u);

            u->son[]=v;

            pushup(v=u);

        }

        return v;

    }

    lct* GetRoot(lct* x) //得到根

    {

        for(x=Access(x);pushdown(x),x->son[]!=null;x=x->son[]) pushup(x);

        return x;

    }

    void MakeRoot(lct* x) //使x成为根

    {

        Access(x);

        Splay(x);

        push_rev(x);

    }

    void Link(lct* x,lct* y) //连接两个点

    {

        MakeRoot(x);

        x->fa=y;

        Access(x);

    }

    void Cut(lct* x,lct* y) //断开两个点

    {

        MakeRoot(x);

        Access(y);

        Splay(y);

        y->son[]->fa=null;

        y->son[]=null;

    }

    void SetC(lct* x,lct* y,int setc)

    {

        MakeRoot(x);

        push_setc(Access(y),setc);

    }

    int Query(lct* x,lct* y)

    {

        MakeRoot(x);

        Access(y);

        Splay(y);

        return y->sum;

    }

}A;

int main()

{

    scanf("%d%d",&N,&M);

    for(int i=;i<=N;i++) scanf("%d",&C[i]);

    A.init(N);

    int x,y;

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

    {

        scanf("%d%d",&x,&y);

        A.Link(A.data+x,A.data+y);

    }

    char op[];

    int c;

    while(M--)

    {

        scanf("%s%d%d",op,&x,&y);

        if(op[]=='C') scanf("%d",&c);

        if(op[]=='C') A.SetC(A.data+x,A.data+y,c);

        else printf("%d\n",A.Query(A.data+x,A.data+y));

    }

    return ;

}