import java.io.*;
import java.util.*;

public class Main {

    public static void main(String[] args) throws IOException {
        InputStream inputStream = new FileInputStream("lca.in");
        OutputStream outputStream = new FileOutputStream("lca.out");

        try (InputReader inputReader = new InputReader(inputStream);
             PrintWriter printWriter = new PrintWriter(outputStream)) {
            int N = inputReader.nextInt();
            int M = inputReader.nextInt();

            Tree tree = new Tree(N);
            for (int node = 2; node <= N; node++) {
                int parent = inputReader.nextInt();
                tree.addEdge(parent, node);
            }

            LCASolver solver = new LCASolver(tree);
            for (int queryNo = 1; queryNo <= M; queryNo++) {
                printWriter.println(solver.getLca(inputReader.nextInt(), inputReader.nextInt()));
            }
        }
    }

    static class LCASolver {

        private Tree tree;

        private int[] depth;

        private int[] eulerPosStart;

        private int[] eulerRepr;

        private int eulerLastPos;

        private int[] log2;

        private int[][] nodeOfMinDepthInInterval;

        public LCASolver(Tree tree) {
            this.tree = tree;
            this.depth = new int[tree.getNumberOfNodes() + 1];
            this.eulerPosStart = new int[tree.getNumberOfNodes() + 1];
            this.eulerRepr = new int[tree.getNumberOfNodes() * 2 + 1];

            Arrays.fill(depth, 0);
            eulerTraversal(tree.getRoot());

            this.log2 = new int[eulerLastPos + 1];
            Arrays.fill(log2, 0);
            for (int i = 2; i <= eulerLastPos; i++) {
                log2[i] = log2[i >> 1] + 1;
            }

            nodeOfMinDepthInInterval = new int[log2[eulerLastPos] + 1][eulerLastPos + 1];
            computeMinDepthIntervals();
        }

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

        private void computeMinDepthIntervals() {
            for (int pos = 1; pos <= eulerLastPos; pos++) {
                nodeOfMinDepthInInterval[0][pos] = eulerRepr[pos];
            }

            for (int depth = 1, intervalLength = 2; depth <= log2[eulerLastPos]; depth++, intervalLength *= 2) {
                // interval: [pos, pos + intervalLength - 1]
                for (int pos = 1; pos <= eulerLastPos - intervalLength + 1; pos++) {
                    nodeOfMinDepthInInterval[depth][pos] = getSmallerNode(
                            nodeOfMinDepthInInterval[depth - 1][pos],
                            nodeOfMinDepthInInterval[depth - 1][pos + intervalLength / 2]);
                }
            }
        }

        private void eulerTraversal(int node) {
            eulerRepr[++eulerLastPos] = node;
            eulerPosStart[node] = eulerLastPos;
            for (int neighbour : tree.getEdges(node)) {
                depth[neighbour] = depth[node] + 1;
                eulerTraversal(neighbour);
                eulerRepr[++eulerLastPos] = node;
            }
        }

        private int getSmallestNodeInInterv(int startInterv, int endInterv) {
            int logIntervLength = log2[endInterv - startInterv + 1];

            return getSmallerNode(
                    nodeOfMinDepthInInterval[logIntervLength][startInterv],
                    nodeOfMinDepthInInterval[logIntervLength][endInterv - (1 << logIntervLength) + 1]);
        }

        public int getLca(int firstNode, int secondNode) {
            // translating the path between the nodes to a path in the euler traversal
            if (eulerPosStart[firstNode] < eulerPosStart[secondNode]) {
                return getSmallestNodeInInterv(eulerPosStart[firstNode], eulerPosStart[secondNode]);
            }
            return getSmallestNodeInInterv(eulerPosStart[secondNode], eulerPosStart[firstNode]);
        }
    }

    static class Tree {

        private int N;

        private List<List<Integer>> edges;

        public Tree(int N) {
            edges = new ArrayList<>(N + 1);
            this.N = N;
            for (int i = 0; i <= N; i++) {
                edges.add(new ArrayList<>());
            }
        }

        public void addEdge(int from, int to) {
            edges.get(from).add(to);
        }

        public List<Integer> getEdges(int from) {
            return edges.get(from);
        }

        public int getNumberOfNodes() {
            return N;
        }

        public int getRoot() {
            return 1;
        }
    }

    static class InputReader implements AutoCloseable {

        private BufferedReader bufferedReader;

        private StringTokenizer stringTokenizer;

        public InputReader(InputStream inputStream) {
            bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
            stringTokenizer = null;
        }

        private String nextToken() {
            if (stringTokenizer == null || !stringTokenizer.hasMoreTokens()) {
                try {
                    stringTokenizer = new StringTokenizer(bufferedReader.readLine());
                } catch (IOException e) {
                    throw new RuntimeException(e);
                }
            }

            return stringTokenizer.nextToken();
        }

        private int nextInt() {
            return Integer.parseInt(nextToken());
        }

        @Override
        public void close() throws IOException {
            bufferedReader.close();
        }
    }
}