#include <bits/stdc++.h>

#define rep(i, j, k) for (int i = (j); i <= (k); ++i)
#define per(i, j, k) for (int i = (j); i >= (k); --i)
#define SZ(v) int((v).size())
#define ALL(v) (v).begin(),(v).end()
#define fi first
#define se second
using ll = long long;
using pii = std::pair<int, int>;
using pll = std::pair<ll, ll>;

template<class T>inline void chkmn(T &x, T y) { if (y < x) x = y; }
template<class T>inline void chkmx(T &x, T y) { if (y > x) x = y; }

using namespace std;

const int maxn = 200010;

int n, m, q, fa[maxn][20], dep[maxn], a[maxn];
vector<int> e[maxn];

void dfs(int u, int f) {
  fa[u][0] = f, dep[u] = dep[f] + 1;
  for (int v : e[u]) if (v != f) dfs(v, u);
}

int lca(int u, int v) {
  if (dep[u] < dep[v]) swap(u, v);
  int dc = dep[u] - dep[v];
  per (i, 19, 0) if (dc >> i & 1) u = fa[u][i];
  if (u == v) return u;
  per (i, 19, 0) if (fa[u][i] == fa[v][i]) u = fa[u][i], v = fa[v][i];
  return fa[u][0];
}

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

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

int main() {
  cin.tie(nullptr) -> ios::sync_with_stdio(false);
  cin >> n >> m >> q;
  rep (i, 1, n - 1) {
    int u, v;
    cin >> u >> v;
    e[u].emplace_back(v);
    e[v].emplace_back(u);
  }
  rep (i, 1, m) cin >> a[i];
  dfs(1, 0);
  rep (j, 1, 19) rep (i, 1, n) fa[i][j] = fa[fa[i][j - 1]][j - 1];
  int ans = 0;
  rep (i, 2, m - 1) if (check(a[i - 1], a[i], a[i + 1])) ans++;
  while (q--) {
    int x, y;
    cin >> x >> y;
    rep (i, max(2, x - 1), min(m - 1, x + 1)) if (check(a[i - 1], a[i], a[i + 1])) ans--;
    a[x] = y;
    rep (i, max(2, x - 1), min(m - 1, x + 1)) if (check(a[i - 1], a[i], a[i + 1])) ans++;
    cout << m - ans << '\n';
  }
}