#include<bits/stdc++.h>
using namespace std;
const int N=2e5+10;
vector<int>v[N];
int a[N],b[N],depth[N],fa[N][20];
void bfs(int root)
{
    memset(depth,0x3f,sizeof depth);
    depth[0] = 0,depth[root] = 1;
    queue<int> q;
    q.push(root);
    while(q.size())
    {
        int t = q.front();
        q.pop();
        for(auto j:v[t])
        {
            if(depth[j]>depth[t]+1)
            {
                depth[j] = depth[t]+1;
                q.push(j);
                fa[j][0] = t;
                for(int k=1;k<=19;k++)
                {
                    fa[j][k] = fa[fa[j][k-1]][k-1];
                }
            }
        }
    }
}
int lca(int a, int b)
{
    if (depth[a] < depth[b]) swap(a, b);
    for (int k = 19; k >= 0; k -- )
        if (depth[fa[a][k]] >= depth[b])
            a = fa[a][k];
    if (a == b) return a;
    for (int k = 19; k >= 0; k -- )
        if (fa[a][k] != fa[b][k])
        {
            a = fa[a][k];
            b = fa[b][k];
        }
    return fa[a][0];
}
int cal(int i)
{
	if(b[i]==0)
	{
		if(b[i+1]==0)  return 0;
		else if(b[i+1]==1)  return 1;
		else  return 1;
	}
	else if(b[i]==1)
	{
		if(b[i+1]==0)
		{
			if(lca(a[i],a[i+2])==a[i]||lca(a[i],a[i+2])==a[i+2])  return 1;
			return 0;
		}
		else if(b[i+1]==1)  return 0;
		else  return 1;
	}
	else
	{
		if(b[i+1]==0)  return 0;
		else if(b[i+1]==1)  return 1;
		else  return 1;
	}
}
int main()
{
	int n,m,q;
	cin>>n>>m>>q;
	for(int i=1;i<n;i++)
	{
		int x,y;
		cin>>x>>y;
		v[x].push_back(y),v[y].push_back(x);
	}
	bfs(1);
	for(int i=1;i<=m;i++)  cin>>a[i];
	for(int i=1;i<m;i++)
	{
		if(lca(a[i],a[i+1])==a[i])  b[i]=0;
		else if(lca(a[i],a[i+1])==a[i+1])  b[i]=1;
		else  b[i]=2;
	}
	int ans=2;
	/*for(int i=1;i<m;i++)  cout<<b[i]<<" ";
	cout<<endl;*/
	for(int i=1;i<m-1;i++)  ans+=cal(i);
	//cout<<ans<<endl;
	while(q--)
	{
		int idx,x,num1=0,num2=0;
		cin>>idx>>x;
		for(int i=max(1,idx-2);i<=min(idx+2,m-2);i++)  num1+=cal(i);
		a[idx]=x;
		for(int i=max(1,idx-2);i<=min(idx+2,m-1);i++)
			if(lca(a[i],a[i+1])==a[i])  b[i]=0;
			else if(lca(a[i],a[i+1])==a[i+1])  b[i]=1;
			else  b[i]=2;
		/*cout<<"a:";
		for(int i=1;i<=m;i++)  cout<<a[i]<<" ";
		cout<<endl;
		cout<<"b:";
		for(int i=1;i<m;i++)  cout<<b[i]<<" ";
		cout<<endl;*/
		for(int i=max(1,idx-2);i<=min(idx+2,m-2);i++)  num2+=cal(i);
		ans+=num2-num1;
		cout<<ans<<endl;
	}
}
/*
5 5 3
2 1
3 2
1 4
5 1
1 5 4 2 3
1 3
5 3
3 3
*/
/*
9 8 1
1 2
2 3
3 4
4 5
1 6
6 7
7 8
8 9
5 1 9 7 5 3 8 4
*/
/*
6 9 1
1 2
1 3
2 4
3 6
3 5
4 5 6 2 4 3 5 1 4
*/