#include <bits/stdc++.h>

using namespace std;

#define MAX_N 100000

int n, m, t, L;
vector <int> tin, tout;
vector <vector <int> > graph, up;
bitset <MAX_N + 1> viz;

void dfs(int node, int parent)
{
    tin[node] = ++t;
    viz[node] = 1;

    up[0][node] = parent;
    for(int i = 1; i <= L ; i ++)
        up[i][node] = up[i - 1][up[i - 1][node]];

    for(int x : graph[node])
        if(!viz[x])
            dfs(x, node);
    tout[node] = ++t;
}

bool isAncestor (int a, int b)
{
    return (tin[a] <= tin[b]  &&  tout[b] <= tout[a]);
}

int lca(int a, int b)
{
    if(isAncestor(a, b))
        return a;
    if(isAncestor(b, a))
        return b;
    int u = a;
    for(int i = L; i >= 0; i --)
    {
        if(!isAncestor(up[i][u], b))
            u = up[i][u];
    }
    return up[0][u];
}

int main()
{
    ios_base :: sync_with_stdio(0);
    cin.tie(0);

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

    cin >> n >> m;
    graph.resize(n + 1);

    for(int i = 2; i <= n; i ++)
    {
        int x;
        cin >> x;
        graph[x].push_back(i);
        graph[i].push_back(x);
    }

    L = log2(n);

    up.resize(L + 1, vector <int> (n + 1));
    tin.resize(n + 1);
    tout.resize(n + 1);
    dfs(1, 1);

    for(int i = 1; i <= m; i ++)
    {
        int a, b;
        cin >> a >> b;
        cout << lca(a, b) << "\n";
    }
    return 0;
}