#include <bits/stdc++.h>

using namespace std;

const int N = 2e5 + 5;

vector<int> G[N];
int m, dep[N], fa[N], siz[N], son[N], top[N], b[N];

void dfs1(int x) {
    siz[x] = 1;
    for (auto v : G[x]) if (v != fa[x]) {
        fa[v] = x, dep[v] = dep[x] + 1;
        dfs1(v);
        siz[x] += siz[v];
        (siz[v] > siz[son[x]]) && (son[x] = v);
    }
}

void dfs2(int x) {
    for (auto v : G[x]) if (v != fa[x]) {
        top[v] = (v == top[x] ? top[x] : v);
        dfs2(v);
    }
}

int LCA(int x, int y) {
    while (top[x] != top[y]) {
        int &z = (dep[top[x]] > dep[top[y]] ? x : y);
        z = fa[top[z]];
    }
    return (dep[x] < dep[y] ? x : y);
}

int dis(int x, int y) {
    return dep[x] + dep[y] - (dep[LCA(x, y)] << 1);
}

int check(int x, int y, int z) {
    return dis(x, y) + dis(y, z) == dis(x, z);
}

int chk(int x) {
    if (x >= 1 && x + 2 <= m) {
        return check(b[x], b[x + 1], b[x + 2]);
    }
    return 0;
}

signed main() {
    int n, q; scanf("%d%d%d", &n, &m, &q);
    for (int i = 1, x, y; i < n; ++i) {
        scanf("%d%d", &x, &y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
    dfs1(dep[1] = 1);
    dfs2(top[1] = 1);
    int res = m;
    for (int i = 1; i <= m; ++i) {
        scanf("%d", &b[i]);
    }
    for (int i = 1; i <= m - 2; ++i) res -= chk(i);
    while (q--) {
        int x, y; scanf("%d%d", &x, &y);
        res += chk(x - 2), res += chk(x - 1), res += chk(x);
        b[x] = y;
        res -= chk(x - 2), res -= chk(x - 1), res -= chk(x);
        printf("%d\n", res);
    }
    return 0;
}