#include <bits/stdc++.h>

using namespace std;

#define     mp              make_pair
#define     fs              first
#define     sc              second
#define     pob             pop_back
#define     pub             push_back
#define     eps             1E-7
#define     sz(a)           a.size()
#define     count_one       __builtin_popcount;
#define     count_onell     __builtin_popcountll;
#define     fastIO          ios_base::sync_with_stdio(false)
#define     PI              (acos(-1.0))
#define     linf            (1LL<<62)//>4e18
#define     inf             (0x7f7f7f7f)//>2e9

#define MAXN 100010

#ifndef ONLINE_JUDGE
ifstream f("lca.in");
ofstream g("lca.out");
#endif

int n, m;
vector<int> child[MAXN];
vector<int> eul, height;
int lft[MAXN], rght[MAXN], tree[MAXN << 4];
int Start, End, hsol, sol;

void euler(int nod, int h) {
    lft[nod] = eul.size();
    rght[eul.size()] = nod;
    eul.pub(nod);
    height.pub(h);
    for(auto it : child[nod]) {
        euler(it, h + 1);
        rght[eul.size()] = nod;
        eul.pub(nod);
        height.pub(h);
    }
}

void queryTree(int nod, int l, int r) {
    if(Start <= l && r <= End) {
        if(height[tree[nod]] < hsol)
            hsol = height[tree[nod]],
            sol = tree[nod];
        return;
    }

    int mid = (l + r) >> 1;
    if(Start <= mid)
        queryTree((nod << 1), l, mid);
    if(mid < End)
        queryTree((nod << 1) + 1, mid + 1, r);
}

void buildTree(int nod, int l, int r) {
    if(l == r) {
        tree[nod] = l;
        return;
    }

    int mid = (l + r) >> 1;
    if(l <= mid)
        buildTree((nod << 1), l, mid);
    if(mid < r)
        buildTree((nod << 1) + 1, mid + 1, r);

    if(height[tree[(nod << 1)]] < height[tree[(nod << 1) + 1]])
        tree[nod] = tree[(nod << 1)];
    else
        tree[nod] = tree[(nod << 1) + 1];
}

int main() {
    f >> n >> m;

    int x;
    for(int i = 2; i <= n; ++i) {
        f >> x;
        child[x].pub(i);
    }

    euler(1, 0);
    buildTree(1, 0, height.size() - 1);

    int a, b;
    while(m--) {
        f >> a >> b;
        sol = hsol = inf;
        if(a > b)
            swap(a, b);
        Start = lft[a]; End = lft[b];
        queryTree(1, 0, height.size() - 1);
        g << rght[sol] << "\n";
    }
    return 0;
}