#include<iostream>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<cstring>
#include<queue>
#include<map>
#define LL long long
using namespace std;
const int mod=998244353;
const int Base=23,Base2=27;
inline int lowbit(int x){return x&(-x);}
inline int Jia(int x){return x>=mod?x-mod:x;}
inline int Jian(int x){return x>=0?x:x+mod;}
int KSM(int a,int b){
	int Ans=1;
	while(b){
		if(b&1)Ans=1LL*Ans*a%mod;
		a=1LL*a*a%mod;
		b>>=1;
	}
	return Ans;
}
inline int read(){
	int k=0,ty=1;
	char ch=getchar();
	while(ch<'0'||ch>'9'){
		if(ch=='-')ty=-1;
		ch=getchar();
	}
	while(ch<='9'&&ch>='0'){
		k=k*10+ch-'0';
		ch=getchar();
	}
	return k*ty;
}
int gcd(int a,int b){
	if(!b)return a;
	return gcd(b,a%b);
}
const int maxn=5e5+5;
int n,m,Q,fa[maxn*2],dept[maxn*2],top[maxn*2],DFN,cnt,h[maxn];
int Size[maxn],Son[maxn],id[maxn],a[maxn],b[maxn],c[maxn],ans;
struct d{
	int to,next;
}E[maxn*2];
void add(int x,int y){
	E[++cnt]=(d){y,h[x]};
	h[x]=cnt;
}
void dfs1(int x,int father,int deep){
	dept[x]=deep;fa[x]=father;
	Size[x]=1;
	for(int i=h[x];i;i=E[i].next){
		int y=E[i].to;
		if(y==fa[x])continue;
		dfs1(y,x,deep+1);
		Size[x]+=Size[y];
		if(Size[y]>Size[Son[x]])Son[x]=y;
	}
}
void dfs2(int x,int Top){
	id[x]=++DFN;top[x]=Top;
	if(!Son[x])return;
	dfs2(Son[x],Top);
	for(int i=h[x];i;i=E[i].next){
		int y=E[i].to;
		if(y==fa[x]||y==Son[x])continue;
		dfs2(y,y);
	}
}
int LCA(int x,int y){
	while(top[x]!=top[y]){
		if(dept[x]<dept[y])swap(x,y);
		x=fa[top[x]];
	}
	if(dept[x]<dept[y])swap(x,y);
	return y;
}
void Check(int p1,int p2,int p3,int ty){
	if(p1<1)return;
	if(p3>m)return;
	p1=a[p1];p2=a[p2];p3=a[p3];
	int t1=LCA(p1,p2),t2=LCA(p2,p3),t3=LCA(p1,p3);
	if(t1==p1){
		if(t2==p2);
		else if(t2==p3)ans+=ty;
		else ans+=ty;
	}
	else if(t1==p2){
		if(t2==p2){
			if(t3!=t2)ans+=ty;
		}
		else if(t2==p3);
		else ;
	}
	else {
		if(t2==p2);
		else if(t2==p1)ans+=ty;
		else ans+=ty;
	}
}
int main(){
//	freopen("data.txt","r",stdin);
	n=read();m=read();Q=read();
	for(int i=1;i<n;++i){
		int x=read(),y=read();
		add(x,y);add(y,x);
	}
	dfs1(1,0,1);
	dfs2(1,1);
	for(int i=1;i<=m;++i){
		a[i]=read();
	}
	ans=0;
	for(int i=1;i<=m;++i){
		Check(i-2,i-1,i,1);
	}
//	for(int i=1;i<=m;++i)cout<<b[i]<<' ';cout<<'\n';
//	for(int i=1;i<=m;++i)cout<<c[i]<<' ';cout<<'\n';
//	cout<<ans<<'\n';
	for(int i=1;i<=Q;++i){
		int x=read(),y=read();
		Check(x-2,x-1,x,-1);
		Check(x-1,x,x+1,-1);
		Check(x,x+1,x+2,-1);
		a[x]=y;
		Check(x-2,x-1,x,1);
		Check(x-1,x,x+1,1);
		Check(x,x+1,x+2,1);
//		for(int i=1;i<=m;++i)cout<<b[i]<<' ';cout<<'\n';
//		for(int i=1;i<=m;++i)cout<<c[i]<<' ';cout<<'\n';
//		cout<<ans<<'\n';
		if(ans==0){
			if(m==1)cout<<1<<'\n';
			else cout<<2<<'\n';
		}
		else {
			cout<<ans+2<<'\n';
		}
	}
	return 0;
}
/*
5 5 5
1 2
2 3
3 4
4 5
1 2 3 4 5
1 1
3 1
5 1
3 3
5 5
*/