#include<bits/stdc++.h>
#define N 200005
using namespace std;
int n,m,q,b[N];
struct edge{
    int to,nxt;
}e[N<<1];
int head[N],cnt;
void add(int u,int v){
    e[++cnt]=(edge){v,head[u]};
    head[u]=cnt;
}
int f[N][20],dep[N];
void dfs(int x,int fa){
    f[x][0]=fa;
    dep[x]=dep[fa]+1;
    for(int i=1;i<=19;++i) f[x][i]=f[f[x][i-1]][i-1];
    for(int i=head[x];i;i=e[i].nxt){
        int v=e[i].to;
        if(v==fa) continue;
        dfs(v,x);
    }
}
int glca(int x,int y){
    if(dep[x]<dep[y]) swap(x,y);
    for(int i=19;i>=0;--i) if(dep[x]-(1<<i)>=dep[y]) x=f[x][i];
    for(int i=19;i>=0;--i) if(f[x][i]!=f[y][i]) x=f[x][i],y=f[y][i];
    return x==y?x:f[x][0];
}
int dis(int x,int y){
    int lca=glca(x,y);
    return dep[x]+dep[y]-2*dep[lca];
}
void sol(){
    cin>>n>>m>>q;
    for(int i=1;i<n;++i){
        int u,v;
        cin>>u>>v;
        add(u,v),add(v,u);
    }
    dfs(1,0);
    for(int i=1;i<=m;++i)
        cin>>b[i];
    int ans=m;
    for(int i=2;i<m;++i)
        if(dis(b[i-1],b[i+1])==dis(b[i-1],b[i])+dis(b[i],b[i+1])){
            --ans;
            // cerr<<"pos "<<i<<endl;
            // cerr<<dis(b[i-1],b[i+1])<<" "<<dis(b[i-1],b[i])<<" "<<dis(b[i],b[i+1])<<endl;
        }
    for(int t=1;t<=q;++t){
        int pos,v;
        cin>>pos>>v;
        for(int i=pos-1;i<=pos+1;++i){
            if(i<2||i>n-1) continue;
            if(dis(b[i-1],b[i+1])==dis(b[i-1],b[i])+dis(b[i],b[i+1]))
                ++ans;
        }
        b[pos]=v;
        for(int i=pos-1;i<=pos+1;++i){
            if(i<2||i>n-1) continue;
            if(dis(b[i-1],b[i+1])==dis(b[i-1],b[i])+dis(b[i],b[i+1]))
                --ans;
        }
        cout<<ans<<'\n';
    }
}
int main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    sol();
    return 0;
}
/*
5 5 3
2 1
3 2
1 4
5 1
1 5 4 2 3
1 3
5 3
3 3
*/