#include <ctime>
#include <iostream>
#include <cassert>
#include <queue>
#include <cmath>
#include <cstring>
#include <algorithm>
#include <bitset>
using namespace std;
//#define int long long
#define debug puts("qwq")
#define open(x) freopen(#x".in", "r", stdin);freopen(#x".out", "w", stdout);
#define close fclose(stdin);fclose(stdout);
#define all(x) x.begin(), x.end()
namespace FastIO {
	template <typename T = int>
	inline T read() {
		T s = 0, w = 1;
		char c = getchar();
		while (!isdigit(c)) {
			if (c == '-') w = -1;
			c = getchar();
		}
		while (isdigit(c)) s = (s << 1) + (s << 3) + (c ^ 48), c = getchar();
		return s * w;
	}
	template <typename T>
	inline void read(T &s) {
		s = 0;
		int w = 1;
		char c = getchar();
		while (!isdigit(c)) {
			if (c == '-') w = -1;
			c = getchar();
		}
		while (isdigit(c)) s = (s << 1) + (s << 3) + (c ^ 48), c = getchar();
		s = s * w;
	}
	template <typename T, typename... Args> inline void read(T &x, Args &...args) {
		read(x), read(args...);
	}
	template <typename T>
	inline void write(T x, char ch) {
		if (x < 0) x = -x, putchar('-');
		static char stk[25];
		int top = 0;
		do {
			stk[top++] = x % 10 + '0', x /= 10;
		} while (x);
		while (top) putchar(stk[--top]);
		putchar(ch);
		return;
	}
	void quit() {
		exit(0);
	}
} using namespace FastIO;
constexpr int N = 1e6 + 19;
int dfn[N], top[N], dep[N], cnt, fa[N], son[N], siz[N], now[N];
vector<int> g[N];
struct node {
	int from, to;
} path[N];
void dfs1(int u, int f) {
	fa[u] = f;
	dep[u] = dep[f] + 1;
	siz[u] = 1;
	for (const int i : g[u]) {
		if (i != f) {
			dfs1(i, u);
			siz[u] += siz[i];
			if (siz[i] > siz[son[u]]) son[u] = i;
		}
	}
}
void dfs2(int u, int f) {
	top[u] = f;
	dfn[u] = ++cnt;
	now[cnt] = u;
	if (son[u]) dfs2(son[u], f);
	for (const int i : g[u]) {
		if (i != son[u] && i != fa[u]) {
			dfs2(i, i);
		}
	}
}
void lca(int &m, int v, int t) {
	int rv = v, len = 0, cnt = 0;
	while (top[m] != top[v]) {
		if (dep[top[m]] < dep[top[v]]) {
			path[++len] = {dfn[v], dfn[top[v]]};
			cnt += dfn[v] - dfn[top[v]] + 1;
			v = fa[top[v]];
		} else {
			int p = dfn[m] - dfn[top[m]] + 1;
			if (t < p) {
				m = dfn[m] - t;
				return ;
			}
			t -= p;
			m = fa[top[m]];
		}
	}
	if (dep[m] < dep[v]) {
		path[++len] = {dfn[v], dfn[m]+1};
		cnt += dfn[v] - dfn[m];
		v = m;
	} else {
		int p = dfn[m] - dfn[v];
		if (t < p) {
			m = dfn[m] - t;
			return ;
		}
		t -= p;
		m = v;
	}
	if (cnt <= t) {
		m = rv;
		return ;
	} else {
		for (int i = len; i; --i) {
			if (t == 0) return ;
			--t; m = now[path[i].to];
			if (t >= path[i].from - path[i].to) {
				t -= path[i].from - path[i].to;
				m = dfn[path[i].from];
			} else {
				m = dfn[path[i].from - t];
				return ;
			}
		}
	}
}
signed main() {
	int n, m, k;
	read(n, m, k);
	for (int i = 1, u, v; i < n; ++i) {
		read(u, v);
		g[u].emplace_back(v);
		g[v].emplace_back(u);
	}
	dfs1(1, 1); dfs2(1, 1);
	while (k--) {
		int v, t;
		read(v, t);
		lca(m, v, t);
		write(m, ' ');
	}
	return 0;
}

有数据。

#1 input https://www.luogu.com.cn/paste/5yny9s7y

output https://www.luogu.com.cn/paste/vd8k22ue