#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>
using namespace std;
const int NMAX = 100505;
const int LMAX = (1 << 18);
const int SQRT_LMAX = (1 << 9);
int N, M;
vector<int> G[NMAX];
int euler[LMAX], firstEuler[NMAX], depth[NMAX], eulerIdx;
int sqrtLowest[SQRT_LMAX], sqrtEuler;
bool visited[NMAX];

void read() {
	scanf("%d%d", &N, &M);
	int x;
	for (int node = 2; node <= N; node++) {
		scanf("%d", &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 precomputeSqrtLowest() {
	sqrtEuler = (int) sqrt(eulerIdx * 1.0) + 1;
	for (int posEuler = 1; posEuler <= eulerIdx; posEuler++) {
		int bucket = posEuler / sqrtEuler;
		sqrtLowest[bucket] = !sqrtLowest[bucket]
			? euler[posEuler] : lowerDepth(sqrtLowest[bucket], euler[posEuler]);
	}
}

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

	int bucketFrom = from / sqrtEuler;
	int bucketTo = to / sqrtEuler;
	int nodeLowestDepth = euler[from];
	if (bucketFrom == bucketTo) {
		for (int posEuler = from + 1; posEuler <= to; posEuler++) {
			nodeLowestDepth = lowerDepth(nodeLowestDepth, euler[posEuler]);
		}
	} else {
		for (int posEuler = from, end = (bucketFrom + 1) * sqrtEuler; posEuler <= end; posEuler++) {
			nodeLowestDepth = lowerDepth(nodeLowestDepth, euler[posEuler]);
		}
		for (int bucketIdx = bucketFrom + 1; bucketIdx < bucketTo; bucketIdx++) {
			nodeLowestDepth = lowerDepth(nodeLowestDepth, sqrtLowest[bucketIdx]);
		}
		for (int posEuler = bucketTo * sqrtEuler; posEuler <= to; posEuler++) {
			nodeLowestDepth = lowerDepth(nodeLowestDepth, euler[posEuler]);
		}
	}
	
	return nodeLowestDepth;
}

void solve() {
	dfs(1);
	precomputeSqrtLowest();

	int x, y;
	for (int queryIdx = 0; queryIdx < M; queryIdx++) {
		scanf("%d%d", &x, &y);
		printf("%d\n", findNodeLowestDepth(firstEuler[x], firstEuler[y]));
	}
}

int main() {
	freopen("lca.in", "r", stdin);
	freopen("lca.out", "w", stdout);

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