#include <bits/stdc++.h>
#define IOS ios::sync_with_stdio(0), cin.tie(0)
#define int long long
#define endl '\n'
#define lowbit(x) (x)&(-x)
#define pii pair<int,int>
#define all(s) s.begin(), s.end()
#define ls(x) (x<<1)
#define rs(x) (x<<1|1) 
#define here system("pause")
using namespace std;

const int N = 2e5+5;
const int mod = 1e9+7;
const int INF = 1e15+7;
const double eps = 1e-6;
inline int pow(int a, int b, int p){ int res = 1%p; while(b){ if(b&1) res=res*a%p; a=a*a%p, b>>=1;} return res;}
inline int inv(int a, int p){ return pow(a,p-2,p)%p;}

int n, m, q;
vector<int> g[N];
int b[N], ok[N];
int f[N][20], dep[N];
inline void dfs(int u, int fa){
	f[u][0] = fa;
	dep[u] = dep[fa] + 1;
	for(int i=1;i<20 && f[u][i-1];i++){
		f[u][i] = f[f[u][i-1]][i];
	}
	for(auto v:g[u]){
		if(v==fa) continue;
		dfs(v, u);
	}
}

inline int getlca(int u, int v){
	if(dep[u]<dep[v]) swap(u, v);
	for(int i=19;i>=0;i--){
		if(dep[f[u][i]]>=dep[v]) u = f[u][i];
	}
	
	if(u==v) return u;
	for(int i=19;i>=0;i--){
		if(f[u][i]!=f[v][i]) u = f[u][i], v = f[v][i];
	}
	return f[v][0];
}

inline int check(int i){ //共链返回0 
	int x = b[i-1], y = b[i], z = b[i+1];
	if(x==z) return 1;
	if(getlca(x, y)==y || getlca(y, z)==y) return 0;
	else return 1; 
}

inline void sol(){
	cin >> n >> m >> q;
	for(int i=1;i<n;i++){
		int u, v;
		cin >> u >> v;
		g[u].push_back(v);
		g[v].push_back(u);
	}
	dfs(1, 0);
	
	for(int i=1;i<=m;i++) cin >> b[i];
	
	for(int i=2;i<m;i++){
		ok[i] = check(i);
	}
	
	int ans = accumulate(ok+1,ok+1+m,0LL);
	
	while(q--){
		int idx, now;
		cin >> idx >> now;
		b[idx] = now;
		
		if(idx==1){
			int delta = ok[2];
			ok[2] = check(2);
			delta -= ok[2];
			ans -= delta;
		}else if(idx==m){
			int delta = ok[m-1];
			ok[m-1] = check(m-1);
			delta -= ok[m-1];
			ans -= delta;
		}else if(idx==2){
			int delta = ok[2];
			ok[2] = check(2);
			delta -= ok[2];
			ans -= delta;
			
			delta = ok[3];
			ok[3] = check(3);
			delta -= ok[3];
			ans -= delta;
		}else if(idx==m-1){
			int delta = ok[m-1];
			ok[m-1] = check(m-1);
			delta -= ok[m-1];
			ans -= delta;
			
			delta = ok[n-2];
			ok[n-2] = check(n-2);
			delta -= ok[n-2];
			ans -= delta;
		}else{
			int delta = ok[idx-1];
			ok[idx-1] = check(idx-1);
			delta -= ok[idx-1];
			ans -= delta;
			
			delta = ok[idx];
			ok[idx] = check(idx);
			delta -= ok[idx];
			ans -= delta;
			
			delta = ok[idx+1];
			ok[idx+1] = check(idx+1);
			delta -= ok[idx+1];
			ans -= delta;
		}
//		for(int i=1;i<=m;i++){
//			cout << " " << b[i];
//		}cout << endl;
//		for(int i=1;i<=m;i++){
//			cout << " " << ok[i];
//		}cout << endl;
		
		cout << ans+2 << endl;
	}
}

signed main(){
	IOS;
	int tc = 1;
	while(tc--){
		sol();
	}
	return 0;
}
/*
10 8 2
1 2
2 3
2 6
6 7
3 5
3 4
1 8
8 9
9 10
4 5 6 2 3 8 4 1
1 4
2 3
*/