#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");
const int maxn = 100005;
vector <int> v[maxn];
vector <int> euler;
int dp[25][maxn];
int prima[maxn];
int log[maxn];
int F[maxn];

void dfs(int nod)
{
    euler.push_back(nod);
    for(auto it : v[nod])
    {
        dfs(it);
        euler.push_back(nod);
    }
}

int main()
{
    int n, m;
    in >> n >> m;
    for(int i = 2; i <= n; i++)
    {
        in >> F[i];
        v[F[i]].push_back(i);
    }
    dfs(1);
    int poz = 1;
    for(auto it : euler)
    {
        if(prima[it] == 0)
            prima[it] = poz;
        poz++;
    }
    for(int i = 2; i < maxn; i++)
        log[i] = log[i / 2] + 1;
    for(int i = 1; i <= (int)euler.size(); i++)
        dp[0][i] = euler[i - 1];
    //for(auto it : euler)
        //cerr << it << " ";
    n = n * 2 - 1;
    for(int i = 1; i <= log[n]; i++)
    {
        for(int j = 1; j <= n; j++)
        {
            int p = (1 << (i - 1));
            if(j + p <= n)
                dp[i][j] = min(dp[i - 1][j], dp[i - 1][j + p]);
            else
                dp[i][j] = dp[i - 1][j];
        }
    }
    //cerr << "\n";
    //cerr << prima[2] << " " << prima[3] << "\n";
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        in >> x >> y;
        x = prima[x];
        y = prima[y];
        if(x > y)
            swap(x, y);
        int dif = y - x + 1;
        int lgdif = log[dif];
        out << min(dp[lgdif][x], dp[lgdif][y - (1 << lgdif) + 1]) << "\n";
    }
    return 0;
}