#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iostream>
using namespace std;
const int NMAX = 100505;
const int LMAX = (1 << 18);
const int HMAX = (1 << 19);
int N, M;
vector<int> G[NMAX];
int euler[LMAX], firstEuler[NMAX], depth[NMAX], eulerIdx;
int segmentTree[HMAX];
bool visited[NMAX];

void read() {
	cin >> N >> M;
	int x;
	for (int node = 2; node <= N; node++) {
		cin >> x;
		G[x].push_back(node);
		G[node].push_back(x);
	}
}

void dfs(int node) {
	visited[node] = true;
	euler[++eulerIdx] = node;
	firstEuler[node] = eulerIdx;
	for (auto neighbour : G[node]) {
		if (!visited[neighbour]) {
			depth[neighbour] = depth[node] + 1;
			dfs(neighbour);
			euler[++eulerIdx] = node;
		}
	}
}

inline int lowerDepth(int node1, int node2) {
	return depth[node1] < depth[node2] ? node1 : node2;
}

void buildSegmentTree(int node, int from, int to) {
	if (from == to) {
		segmentTree[node] = euler[from];
		return;
	}
	int mid = (from + to) / 2;
	buildSegmentTree(node * 2, from, mid);
	buildSegmentTree(node * 2 + 1, mid + 1, to);

	segmentTree[node] = lowerDepth(segmentTree[node * 2], segmentTree[node * 2 + 1]);
}

int query(int node, int from, int to, int queryFrom, int queryTo) {
	if (queryTo < from || to < queryFrom) {
		return -1;
	}

	if (queryFrom <= from && to <= queryTo) {
		return segmentTree[node];
	}

	int mid = (from + to) / 2;
	int candidateLeft = query(node * 2, from, mid, queryFrom, queryTo);
	int candidateRight = query(node * 2 + 1, mid + 1, to, queryFrom, queryTo);

	if (candidateLeft == -1 || candidateRight == -1) {
		return (candidateLeft == -1) ? candidateRight : candidateLeft;
	}
	return lowerDepth(candidateLeft, candidateRight);
}

int findNodeLowestDepth(int from, int to) {
	if (from > to) {
		swap(from, to);
	}

	return query(1, 1, eulerIdx, from, to);
}

void solve() {
	dfs(1);
	buildSegmentTree(1, 1, eulerIdx);

	int x, y;
	for (int queryIdx = 0; queryIdx < M; queryIdx++) {
		cin >> x >> y;
		cout << findNodeLowestDepth(firstEuler[x], firstEuler[y]) << "\n";
	}
}

int main() {
	freopen("lca.in", "r", stdin);
	freopen("lca.out", "w", stdout);
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);

	read();
	solve();
	return 0;
}