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

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    int n, m, q;
    cin >> n >> m >> q;

    vector<vector<int>> adj(n + 1);
    for (int i = 1; i <= n - 1; i++) {
    	int x, y;
    	cin >> x >> y;
    	adj[x].push_back(y);
    	adj[y].push_back(x);
    }

    vector<int> b(m + 1), c(m + 1, 1), dep(n + 1);
    vector<array<int, 32>> f(n + 1);
    auto dfs = [&](auto &&self, int x, int fa = 1) -> void {
    	f[x][0] = fa;
    	dep[x] = dep[fa] + 1;
    	for (auto y : adj[x]) {
    		if (y == fa) continue;
    		self(self, y, x);
    	}
    	for (int j = 1; j <= 20; j++) {
    		f[x][j] = f[f[x][j - 1]][j - 1];
    	}
    };

    dfs(dfs, 1);

    auto lca = [&](int x, int y) -> int {
    	if (dep[x] < dep[y]) swap(x, y);
    	for (int j = 20; j >= 0; j--) {
    		if (dep[f[x][j]] >= dep[y]) {
    			x = f[x][j];
    		}
    	}
    	if (x == y) return x;
    	for (int j = 20; j >= 0; j--) {
    		if (f[x][j] != f[y][j]) {
    			x = f[x][j];
    			y = f[y][j];
    		}
    	}
    	return f[x][0];
    };

    for (int i = 1; i <= m; i++) {
    	cin >> b[i];
    }

    int res = m;
    auto upd = [&](int x, int y) -> void {
		int l1 = lca(b[y], b[x]), l2 = lca(b[x], b[x + 1]), l3 = lca(b[y], b[x + 1]);
    	if (l2 == l1 && l3 == b[x + 1]) {
    		if (c[x + 1]) {
    			res -= c[x + 1];
	    		c[x + 1] ^= 1;
	    		res += c[x + 1];
    		}
    	} else if (l3 == l1 && l2 == b[x + 1]) {
    		if (c[x + 1]) {
    			res -= c[x + 1];
	    		c[x + 1] ^= 1;
	    		res += c[x + 1];
    		}
    	} else {
    		if (!c[x + 1]) {
				res -= c[x + 1];
	    		c[x + 1] ^= 1;
	    		res += c[x + 1];
    		}
    	}
    };

    for (int i = 3; i <= m; i++) {
    	upd(i - 2, i);
    }

    while (q--) {
    	int x, y;
    	cin >> x >> y;
    	b[x] = y;
    	if (x - 2 >= 1) {
    		upd(x - 2, x);
    	}
    	if (x + 2 <= m) {
    		upd(x, x + 2);
    	}
    	if (x - 1 >= 1 && x + 1 <= m) {
    		upd(x - 1, x + 1);
    	}
    	cout << res << "\n";
    }



    return 0;
}