#include<bits/stdc++.h>
#define int long long
using namespace std;
const int N=1e6+7,inf=1e18,mod=998244353,S=21;
int n,m,Q;
vector<vector<int>> e,fa;
vector<int> dep;
void dfs(int u)
{
	dep[u]=dep[fa[u][0]]+1;
	for(auto v:e[u])
	{
		if(v==fa[u][0]) continue;
		fa[v][0]=u;
		dfs(v);
	}
	for(int i=1; i<S; i++)
	{
		fa[u][i]=fa[fa[u][i-1]][i-1];
	}
}
int lca(int x,int y)
{
	if(dep[x]<dep[y]) swap(x,y);
	for(int i=S-1; i>=0; i--)
	{
		if(dep[fa[x][0]]>=dep[y])
		{
			x=fa[x][0];
		}
	}
	if(x==y) return x;
	for(int i=S-1; i>=0; i--)
	{
		if(fa[x][i]!=fa[y][i])
		{
			x=fa[x][i];
			y=fa[y][i];
		}
	}
	return fa[x][0];
}
void O_o()
{
	cin>>n>>m>>Q;
	e.assign(n+1,vector<int>());
	fa.assign(n+1,vector<int>(S,0));
	dep.assign(n+1,0);
	for(int i=1; i<n; i++)
	{
		int x,y;
		cin>>x>>y;
		e[x].push_back(y);
		e[y].push_back(x);
	}
	dfs(1);
	vector<int> b(2*m),ls(2*m);
	vector<bool> del(2*m,0);
	cin>>b[1];
	for(int i=2; i<=m; i++)
	{
		cin>>b[i*2-1];
		b[i*2-2]=lca(b[i*2-3],b[i*2-1]);
	}
	ls[2]=1;
	int tot=0;
	for(int i=2; i<2*m-1; i++)
	{
		int l1=lca(b[ls[i]],b[i]),l2=lca(b[i],b[i+1]),l3=lca(b[ls[i]],b[i+1]);
		if((l1==b[i]||l2==b[i]||l3==b[i])&&b[ls[i]]!=b[i+1])
		{
//			if(i&1)
//				cout<<i/2+1<<"\n";
			del[i]=1;
			tot++;
			ls[i+1]=ls[i];
		}
		else
		{
			del[i]=0;
			ls[i+1]=i;
		}
	}
//	cout<<2*n-1-tot<<"\n";
	while(Q--)
	{
		int id,x;
		cin>>id>>x;
		id=id*2-1;
		b[id]=x;
		if(id>1)
		{
			b[id-1]=lca(b[id-2],b[id]);
		}
		if(id<m*2-1)
		{
			b[id+1]=lca(b[id],b[id+2]);
		}
		for(int i=max(2ll,id-4); i<=min(2*m-1,id+4); i++)
		{
			tot-=del[i];
			int l1=lca(b[ls[i]],b[i]),l2=lca(b[i],b[i+1]),l3=lca(b[ls[i]],b[i+1]);
			if((l1==b[i]||l2==b[i]||l3==b[i])&&b[ls[i]]!=b[i+1])
			{
				del[i]=1;
				tot++;
				ls[i+1]=ls[i];
			}
			else
			{
				del[i]=0;
				ls[i+1]=i;
			}
		}
		cout<<2*m-1-tot<<"\n";
	}
}
signed main()
{
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
	cout<<fixed<<setprecision(12);
	int T=1;
//	cin>>T;
	while(T--)
	{
		O_o();
	}
}