#include <bits/stdc++.h>

using namespace std;

ifstream F("lca.in");
ofstream G("lca.out");

int n, m, x, y, k, lvl[200005], eul[200005], h[100005], t[100005], dp[200005][20];
vector<int> a[100005];
bitset<100005> v;

void dfs(int nod)
{
    vector<int> :: iterator it;
    v[nod] = 1;
    if(nod != 1) lvl[++ k] = lvl[h[t[nod]]] + 1;
    else ++ k;
    if(!h[nod]) h[nod] = k;
    eul[k] = nod;
    for(it = a[nod].begin(); it != a[nod].end(); ++ it)
        if(!v[*it])
        {
            dfs(*it);
            if(nod != 1) lvl[++ k] = lvl[h[t[nod]]] + 1;
            else ++ k;
            eul[k] = nod;
        }
}

void make_dp()
{
    for(int i = 0; i < k; ++ i) dp[i][0] = i;
    for(int j = 1; (1 << j) <= k; ++ j)
        for(int i = 0; i + (1 << j)-1 < k; ++ i)
            if(lvl[dp[i][j-1]] < lvl[dp[i + (1 << (j - 1))][j-1]])
                dp[i][j] = dp[i][j-1];
            else dp[i][j] = dp[i + (1 << (j - 1))][j-1];
}

int rmq(int l, int h)
{
    int lng = h - l + 1;
    int K = 1, p = 0;
    for(K = 1; K <= lng; K <<= 1, p++);
    if(K > lng) K/=2, --p;
    return min(eul[dp[l][p]], eul[dp[l+lng-(1 << p)][p]]);
}

int main()
{
    F >> n >> m;
    for(int i = 2; i <= n; ++ i) F >> t[i], a[t[i]].push_back(i);
    for(int i = 1; i <= n; ++ i)
        if(!v[i]) dfs(i);
    make_dp();
    for(int i = 1; i <= m; ++ i)
    {
        F >> x >> y;
        if(h[x] > h[y]) swap(x, y);
        G << rmq(h[x], h[y]) << '\n';
    }
    return 0;
}