//Author: Kevin
#include<bits/stdc++.h>
//#pragma GCC optimize("O2")
using namespace std;
#define ll long long
#define ull unsigned ll
#define pb emplace_back
#define mp make_pair
#define ALL(x) (x).begin(),(x).end()
#define rALL(x) (x).rbegin(),(x).rend()
#define srt(x) sort(ALL(x))
#define rev(x) reverse(ALL(x))
#define rsrt(x) sort(rALL(x))
#define sz(x) (int)(x.size())
#define inf 0x3f3f3f3f
#define pii pair<int,int>
#define lb(v,x) (int)(lower_bound(ALL(v),x)-v.begin())
#define ub(v,x) (int)(upper_bound(ALL(v),x)-v.begin())
#define uni(v) v.resize(unique(ALL(v))-v.begin())
#define longer __int128_t
void die(string S){puts(S.c_str());exit(0);}
int n,m,q;
int b[200200];
vector<int> G[200200];
int depth[200200],anc[18][200200];
void dfs(int u,int fa)
{
	depth[u]=depth[fa]+1;
	anc[0][u]=fa;
	for(auto v:G[u])
		if(v!=fa)
			dfs(v,u);
}
inline int lca(int u,int v)
{
	for(int i=17;i>=0;i--)
	{
		if(depth[anc[i][u]]>=depth[v])
			u=anc[i][u];
		if(depth[anc[i][v]]>=depth[u])
			v=anc[i][v];
	}
	if(u==v) return u;
	for(int i=17;i>=0;i--)
		if(anc[i][u]!=anc[i][v])
		{
			u=anc[i][u];
			v=anc[i][v];
		}
	return anc[0][u];
}
inline int dist(int x,int y)
{
	return depth[x]+depth[y]-depth[lca(x,y)]*2;
}
inline bool onChain(int x,int y,int z)
{
	return dist(x,y)+dist(y,z)==dist(x,z);
}
int main()
{
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin>>n>>m>>q;
	for(int i=1;i<n;i++)
	{
		int u,v;
		cin>>u>>v;
		G[u].pb(v);
		G[v].pb(u);
	}
	dfs(1,0);
	for(int i=1;i<18;i++)
		for(int j=1;j<=n;j++)
			anc[i][j]=anc[i-1][anc[i-1][j]];
	for(int i=1;i<=n;i++)
		cin>>b[i];
	int ans=n;
	for(int i=2;i<n;i++)
		ans-=onChain(b[i-1],b[i],b[i+1]);
	while(q--)
	{
		int u,v;
		cin>>u>>v;
		for(int i=max(2,u-1);i<=min(n-1,u+1);i++)
			ans+=onChain(b[i-1],b[i],b[i+1]);
		b[u]=v;
		for(int i=max(2,u-1);i<=min(n-1,u+1);i++)
			ans-=onChain(b[i-1],b[i],b[i+1]);
		cout<<ans<<'\n';
	}
	return 0;
}