#include<cstdio>

#include<cstring>

#include<algorithm>

#define ll long long

#define ls Ls[cr]

#define rs Rs[cr]

using namespace std;

const int N=1e5+,K=;

int n,hd[N],xnt,to[N<<],nxt[N<<],rt;

int dep[N],fa[N],pre[N][K],c[N][],dfn[N],siz[N],tot;

int sta[N],top; ll tmp[N],f[N],fi[N]; bool rev[N];

int rdn()

{

  int ret=;bool fx=;char ch=getchar();

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

  while(ch>=''&&ch<='')ret=ret*+ch-'',ch=getchar();

  return fx?ret:-ret;

}

void add(int x,int y){to[++xnt]=y;nxt[xnt]=hd[x];hd[x]=xnt;}

void dfs(int cr)

{

  dfn[cr]=++tot;siz[cr]=;

  dep[cr]=dep[fa[cr]]+;tmp[tot]=dep[cr];

  pre[cr][]=fa[cr];

  for(int i=;pre[pre[cr][i-]][i-];i++)

    pre[cr][i]=pre[pre[cr][i-]][i-];

  for(int i=hd[cr],v;i;i=nxt[i])

    if(!dfn[v=to[i]])

      {

    fa[v]=cr;dfs(v);

        siz[cr]+=siz[v];

      }

}

void add(int x,ll k,ll *f){for(;x<=n;x+=(x&-x))f[x]+=k;}//ll k! for init

ll qry(int x,ll *f){ll ret=;for(;x;x-=(x&-x))ret+=f[x];return ret;}

ll qry(int x)

{

  ll ret=;int yx=x+;

  for(;x;x-=(x&-x))ret+=(ll)yx*f[x]-fi[x];return ret;

}

void init()

{

  for(int i=n;i;i--)tmp[i]-=tmp[i-],add(i,tmp[i],f);

  for(int i=;i<=n;i++)tmp[i]*=i,add(i,tmp[i],fi);

}

void mdfy(int L,int R,int k)

{

  if(L>R)return;/////

  add(L,k,f);add(R+,-k,f);

  add(L,k*L,fi);add(R+,-k*(R+),fi);

}

ll query(int L,int R)

{

  if(L>R)return ;///

  ll a=(R+)*qry(R,f)-qry(R,fi);

  ll b=L*qry(L-,f)-qry(L-,fi);

  return a-b;

}

bool isroot(int x){return c[fa[x]][]!=x&&c[fa[x]][]!=x;}

void Rev(int x)

{

  if(!rev[x])return;rev[x]=;

  rev[c[x][]]^=;rev[c[x][]]^=;

  swap(c[x][],c[x][]);

}

void rotate(int x)

{

  int y=fa[x],z=fa[y],d=(x==c[y][]);

  if(!isroot(y))c[z][y==c[z][]]=x;

  fa[x]=z;

  fa[c[x][!d]]=y;fa[y]=x;

  c[y][d]=c[x][!d];c[x][!d]=y;

}

void splay(int x)

{

  sta[top=]=x;

  for(int k=x;!isroot(k);k=fa[k])sta[++top]=fa[k];

  for(int i=top;i;i--)Rev(sta[i]);

  int y,z;

  while(!isroot(x))

    {

      y=fa[x];z=fa[y];

      if(!isroot(y))

    ((x==c[y][])^(y==c[z][]))?rotate(x):rotate(y);

      rotate(x);

    }

}

int fnd(int x)

{Rev(x);while(c[x][])x=c[x][],Rev(x);return x;}

int fnd(int x,int f)

{

  for(int i=;i>=;i--)

    if(dep[pre[x][i]]>dep[f])x=pre[x][i];

  return x;

}

bool intree(int x,int rt)

{return dfn[x]>=dfn[rt]&&dfn[x]<dfn[rt]+siz[rt];}

void chg(int x,int k)

{

  if(!intree(rt,x))mdfy(dfn[x],dfn[x]+siz[x]-,k);

  else

    {

      int d=fnd(rt,x);//d!!

      mdfy(,dfn[d]-,k);mdfy(dfn[d]+siz[d],n,k);

    }

}

void access(int x)

{

  int t=;

  while(x)

    {

      splay(x);

      if(c[x][])chg(fnd(c[x][]),);

      if(t)chg(fnd(t),-);

      c[x][]=t;

      t=x;x=fa[x];

    }

}

void makeroot(int x)

{

  access(x);splay(x);rev[x]^=;rt=x;//rt=x after access(x)

}

double query(int x)

{

  if(x==rt) return (double)query(,n)/n;

  if(intree(rt,x))

    {

      int d=fnd(rt,x);

      ll ret=query(,dfn[d]-)+query(dfn[d]+siz[d],n);

      return (double)ret/(n-siz[d]);

    }

  return (double)query(dfn[x],dfn[x]+siz[x]-)/siz[x];

}

int main()

{

  n=rdn();int Q=rdn();

  for(int i=,u,v;i<n;i++)

    {

      u=rdn();v=rdn();add(u,v);add(v,u);

    }

  dfs();init();

  char ch[];int x;rt=;

  while(Q--)

    {

      scanf("%s",ch);x=rdn();

      if(ch[]=='L')access(x);

      if(ch[]=='C')makeroot(x);

      if(ch[]=='Q')printf("%.10f\n",query(x));

    }

  return ;

}