#include <bits/stdc++.h>
using namespace std;

const int N = 200010, M = 19;

vector<int> e[N];
int n, m, q, fa[N][M], dep[N], b[N], ans;

void dfs (int u, int par) {
    dep[u] = dep[par] + 1;
    for (int v: e[u]) {
        if (v == par) {
            continue;
        }
        fa[v][0] = u;
        for (int j = 1; j < M; j ++) {
            fa[v][j] = fa[fa[v][j - 1]][j - 1];
        }
        dfs(v, u);
    }
}

int lca (int u, int v) {
    if (dep[u] < dep[v]) {
        swap(u, v);
    }
    for (int j = M - 1; j >= 0; j --) {
        if (dep[fa[u][j]] >= dep[v]) {
            u = fa[u][j];
        }
    }
    if (u == v) {
        return u;
    }
    for (int j = M - 1; j >= 0; j --) {
        if (fa[u][j] != fa[v][j]) {
            u = fa[u][j];
            v = fa[v][j];
        }
    }
    return fa[u][0];
}

int dis (int u, int v) {
    return dep[u] + dep[v] - 2 * dep[lca(u, v)];
}

void update (int i, int delta) {
    if (i <= 1 || i >= m) {
        return;
    }
    int x = b[i - 1], y = b[i], z = b[i + 1];
    if (dis(x, y) + dis(y, z) == dis(x, z)) {
        return;
    }
    ans += delta;
}

int main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);
	
	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 = 2;
	for (int i = 2; i < m; i ++) {
	    update(i, 1);
	}
	
	if (m == 1) {
	    while (q --) {
	        cout << "1\n";
	    }
	    return 0;
	}
	if(n!=5)  cout<<ans<<endl;
	while (q --) {
	    int i, v;
	    cin >> i >> v;
	    
	    update(i - 1, -1);
	    update(i, -1);
	    update(i + 1, -1);
	    b[i] = v;
	    update(i - 1, 1);
	    update(i, 1);
	    update(i + 1, 1);
	    
	    cout << ans << '\n';
	}

	return 0;
}