#include <bits/stdc++.h>
using namespace std;using ll=long long;using ld=long double;using ull=unsigned long long;
using PII=pair<ll,ll>;using pii=pair<int,int>;const ll M=998244353;const ll INF=1e17;
const double eps=1e-10;const double PI=acos(-1.0);const int inf=1e9+7;
int n,m,q,L[200005],cnt,R[200005],b[200005],f[200005],ans[200005],sum;
vector<int>e[200005];
void dfs(int u,int fa){
    L[u]=++cnt;
    for(auto v:e[u]){
        if(v==fa)continue;
        dfs(v,u);
    }
    R[u]=cnt;
}
bool ch(int x,int y){
    return (L[y]>=L[x]&&L[y]<=R[x]);
}
void update(int x){
    if(x==1||x>m){
        return;
    }
    
    if(ch(b[x],b[x-1])){
        f[x]=1;
    }else{
        f[x]=-1;
    }
    
    if((f[x]==-1&&ch(b[x-1],b[x])&&f[x-1]==-1)||(f[x]==1&&f[x-1]==1)||(f[x-1]==1&&f[x]==-1&&!ch(b[x-1],b[x]))){
        if(f[x]==1&&f[x-1]==1)assert(ch(b[x],b[x-1]));
        if(ans[x]==1)sum--;
        ans[x]=0;
    }else{
        if(ans[x]==0)sum++;
        ans[x]=1;
    }
}
signed main(){
    ios::sync_with_stdio(false),cin.tie(nullptr);
    cin>>n>>m>>q;
    for(int i=1;i<n;i++){
        int u,v;cin>>u>>v;
        e[u].push_back(v);
        e[v].push_back(u);
    }
    dfs(1,0);
    
    for(int i=1;i<=m;i++){
        cin>>b[i];
    }
    
    ans[1]=1;
    f[1]=0;
    sum=1;
    
    for(int i=2;i<=m;i++){
        update(i);
    }
    
    for(int i=1;i<=q;i++){
        int p,w;cin>>p>>w;
        b[p]=w;
        update(p);
        update(p+1);
        update(p+2);
        assert(sum>=2&&sum<=m);
        cout<<sum<<"\n";
    }
}

/*


5 5 3
2 1
3 2
1 4
5 1
1 5 4 2 3
1 3
5 3
3 3

*/