#include<iostream>
#include<cstdio>
#include<cstring>
#include<queue>
#include<vector>
using namespace std;
const int N = 2e5 + 5;

int n, m, qr, p, g, b[N], ans;
int fa[N][22], deg[N];
bool f[N];

struct Edge{
    int to, nxt;
}edge[N * 2];
int head[N], tot;
void addedge(int uu, int vv){
    edge[tot].to = vv;
    edge[tot].nxt = head[uu];
    head[uu] = tot++;
}
void init(){
    tot = 0;
    memset(head, -1, sizeof(head));
}

void bfs(int root){
    queue<int> que;
    deg[root] = 0;
    fa[root][0] = root;
    que.push(root);
    while(!que.empty()){
        int tmp = que.front();
        que.pop();
        for(int i = 1; i <= 20; i++){
            fa[tmp][i] = fa[fa[tmp][i - 1]][i - 1];
        }
        for(int i = head[tmp]; i != -1; i = edge[i].nxt){
            int v = edge[i].to;
            if(v == fa[tmp][0]) continue;
            deg[v] = deg[tmp] + 1;
            fa[v][0] = tmp;
            que.push(v);
        }
    }
}

int lca(int u, int v){
    if(deg[u] > deg[v]) swap(u, v);
    int hu = deg[u], hv = deg[v];
    int tu = u, tv = v;
    for(int det = hv - hu, i = 0; det; det >>= 1, i++){
        if(det & 1) tv = fa[tv][i];
    }
    if(tu == tv) return tu;
    for(int i = 20; i>= 0; i--){
        if(fa[tu][i] == fa[tv][i]) continue;
        tu = fa[tu][i];
        tv = fa[tv][i];
    }
    return fa[tu][0];
}

void check(int i){
    int l = 0, r = 0, z = 0, ret;
    ret = lca(b[i - 1], b[i + 1]);
    if(ret == b[i - 1]) l++;
    else if(ret == b[i + 1]) r++;
    ret = lca(b[i - 1], b[i]);
    if(ret == b[i - 1]) l++;
    else if(ret == b[i]) z++;
    ret = lca(b[i], b[i + 1]);
    if(ret == b[i]) z++;
    else if(ret == b[i + 1]) r++;
    
    if(f[i] == 1){
        if(l == 2 && z == 1) f[i] = 0;
        else if(r == 2 && z == 1) f[i] = 0;
        else if(l == 0 && r == 0 && (z == 1 || z == 3)){
            f[i] = 0;
        }
        if(b[i] == b[i + 1]) f[i] = 0;
        if(f[i] == 0) ans--;
    }
    else{
        if(l == 2 && z == 1) f[i] = 0;
        else if(r == 2 && z == 1) f[i] = 0;
        else if(l == 0 && r == 0 && (z == 1 || z == 3)){
            f[i] = 0;
        }
        else if(b[i] == b[i + 1]) f[i] = 0;
        else{
            f[i] = 1;
            ans++;
        }
    }
}

int main(){
    scanf("%d%d%d", &n, &m, &qr);
    
    init();
    int u, v;
    for(int i = 1; i < n; i++){
        scanf("%d%d", &u, &v);
        addedge(u, v);
        addedge(v, u);
    }
    for(int i = 1; i <= m; i++){
        scanf("%d", &b[i]);
    }
    for (int i = 1; i <= n; ++i) {
        for (int j = 1; j <= 20; ++j) {
            fa[i][j] = fa[fa[i][j-1]][j-1];
        }
    }
    bfs(1);
    f[1] = 1;
    f[m] = 1;
    for(int i = 2; i < m; i++){
        int l = 0, r = 0, z = 0, ret;
        ret = lca(b[i - 1], b[i + 1]);
        if(ret == b[i - 1]) l++;
        else if(ret == b[i + 1]) r++;
        ret = lca(b[i - 1], b[i]);
        if(ret == b[i - 1]) l++;
        else if(ret == b[i]) z++;
        ret = lca(b[i], b[i + 1]);
        if(ret == b[i]) z++;
        else if(ret == b[i + 1]) r++;
        
        f[i] = 1;
        if(l == 2 && z == 1) f[i] = 0;
        else if(r == 2 && z == 1) f[i] = 0;
        else if(l == 0 && r == 0 && (z == 1 || z == 3)){
            f[i] = 0;
        }
    }
    ans = 0;
    for(int i = 1; i <= m; i++){
        if(f[i]) ans++;
    }
    while(qr--){
        scanf("%d%d", &p, &g);
        b[p] = g;
        if(p > 1 && p < m) check(p);
        if(p - 1 > 1 && p - 1 < m) check(p - 1);
        if(p + 1 > 1 && p + 1 < m) check(p + 1);
        printf("%d\n", ans);
    }
    return 0;
}