#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], d[200005][20], q, r;
vector<int> a[100005];
bitset<100005> v;

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

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

int rmq( int x, int y )
{
    int p = 0;
    while((1<<p)<=(y-x+1)) p++;
    if((1<<p)>(y-x+1)) p--;
    return min(eul[d[p][x]], eul[d[p][y-(1<<p)+1]]);
}

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();
    while(m--)
    {
        F >> q >> r;
        if(h[q]>h[r]) swap(q, r);
        G << rmq(h[q], h[r]) << '\n';
    }
    return 0;
}