#include<bits/stdc++.h>
using namespace std;
#define cs const
#define re register
#define pb push_back
#define pii pair<int,int>
#define ll long long
#define fi first
#define se second
#define bg begin
#define gc getchar
inline int read(){
	char ch=gc();
	int res=0;bool f=1;
	while(!isdigit(ch))f^=ch=='-',ch=gc();
	while(isdigit(ch))res=(res+(res<<2)<<1)+(ch^48),ch=gc();
	return f?res:-res;
}
template<typename tp>inline void chemx(tp &a,tp b){(a<b)?(a=b):0;}
template<typename tp>inline void chemn(tp &a,tp b){(a>b)?(a=b):0;}

cs int N=200005;

int n,m,q;
int fa[N][20],dep[N],b[N];
vector<int> e[N];
int LCA(int u,int v){
    if(dep[u]<dep[v])swap(u,v);
    for(int i=19;~i;i--)if(dep[fa[u][i]]>=dep[v])u=fa[u][i];
    if(u==v)return v;
    for(int i=19;~i;i--)if(fa[u][i]!=fa[v][i]){
        u=fa[u][i],v=fa[u][i];
    }
    return fa[u][0];
}

int dis(int u,int v){
    return dep[u]+dep[v]-2*dep[LCA(u,v)];
}

int calc(int a,int b,int c){
    //cout<<a<<" "<<b<<" "<<c<<" "<<dis(a,b)<<" "<<dis(b,c)<<" "<<dis(a,c)<<'\n';
    if(dis(a,b)+dis(b,c)==dis(a,c))return 0;
    else return 1;
}

void dfs(int u,int ff){
    for(int i=1;i<20;i++)fa[u][i]=fa[fa[u][i-1]][i-1];
    for(int v:e[u])if(v!=ff){
        fa[v][0]=u;
        dep[v]=dep[u]+1;
        dfs(v,u);
    }
}

int main(){
 //   freopen("1.in","r",stdin);
    n=read(),m=read(),q=read();
    for(int i=1;i<n;i++){
        int u=read(),v=read();
        e[u].pb(v),e[v].pb(u);
    }
    dep[1]=1;
    dfs(1,0);
    for(int i=1;i<=m;i++)b[i]=read();
    int ans=2;
    for(int i=2;i<m;i++)ans+=calc(b[i-1],b[i],b[i+1]);
   // cout<<ans<<'\n';exit(0);
    while(q--){
        int p=read(),v=read();
        if(p>2)ans-=calc(b[p-2],b[p-1],b[p]);
        if(p+1<m)ans-=calc(b[p],b[p+1],b[p+2]);
        if(p>1&&p<m)ans-=calc(b[p-1],b[p],b[p+1]);
        b[p]=v;
        if(p>2)ans+=calc(b[p-2],b[p-1],b[p]);
        if(p+1<m)ans+=calc(b[p],b[p+1],b[p+2]);
        if(p>1&&p<m)ans+=calc(b[p-1],b[p],b[p+1]);
        if(m==1)cout<<1<<'\n';
        else cout<<ans<<'\n';
    }
}