#include <bits/stdc++.h>

using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
const int nmax = 1e5+2;
void dfs(int nod, int niv);

vector<int> adj[nmax];
struct ura
{
    int nod, lvl;
    bool operator < (const ura& aux) const
    {
        return lvl < aux.lvl;
    }
}rmq[18][2*nmax];

int n, m, euler, first[nmax], lg2[2*nmax];

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

    for(int i = 2; i <= n; ++i)
    {
        int x;
        fin>>x;
        adj[x].push_back(i);
    }
    dfs(1, 0);

    for(int p = 1; (1<<p) <= euler; ++p)
    {
        for(int i = 1; i <= euler; ++i)
        {
            rmq[p][i] = rmq[p-1][i];
            int j = i + (1<<(p-1));
            if(i + (1<<p) <= euler)
                rmq[p][i] = min(rmq[p][i], rmq[p-1][j]);
        }
    }
    for(int i = 2; i <= euler; ++i)
        lg2[i] = lg2[i/2] + 1;

    while(m--)
    {
        int x, y;
        fin>>x>>y;
        x = first[x]; y = first[y];
        if(x > y)
            swap(x, y);

        int p = lg2[y - x + 1];
        ura ans = min(rmq[p][x], rmq[p][y-(1<<p)+1]);
        fout<<ans.nod<<"\n";
    }



    return 0;
}

void dfs(int nod, int niv)
{
    rmq[0][++euler] = {nod, niv};

    if(!first[nod])
        first[nod] = euler;

    for(auto f : adj[nod])
    {
        dfs(f, niv+1);
        rmq[0][++euler] = {nod, niv};
    }
}