#include <iostream>
#include <fstream>
#include <vector>
#include <stack>
#include <list>
using namespace std;

#define maxn 100005
#define maxl 20


ifstream be("lca.in");
ofstream ki("lca.out");

int e[maxn<<1],k,first[maxn],h[maxn<<1],n,m,lg[maxn<<1];
int rmq[maxl][maxn<<2];
vector<bool>ell(maxn+1,false);
int l[maxn<<1];
vector<vector<int> >adj(maxn);

void dfs(int start,int lev)
{
    h[++k]=start;
    l[k]=lev;
    first[start]=k;
    ell[start]=true;
    for(int sz:adj[start]){
        if(!(ell[sz])){
            dfs(sz,lev+1);
            h[++k]=start;
            l[k]=lev;
        }

    }
}



void rmq1()
{
    for(int i = 2; i <= k; ++i)
        lg[i] = lg[i >> 1] + 1;

    for(int i = 1; i <= k; ++i)
        rmq[0][i] = i;

    for(int i = 1; (1 << i) < k; ++i)
        for(int j = 1; j <= k - (1 << i); ++j)
        {
            int logaritm = 1 << (i - 1);
            rmq[i][j] = rmq[i-1][j];
            if(l[rmq[i-1][j + logaritm]] < l[rmq[i][j]])
                rmq[i][j] = rmq[i-1][j + logaritm];
        }
}

int lca_function(int x,int y)
{
    int diff, logaritm, sol, sh;
    int a = first[x], b = first[y];
    if(a > b) swap(a, b);
    diff = b - a + 1;
    logaritm = lg[diff];
    sol = rmq[logaritm][a];
    sh = diff - (1 << logaritm);
    if(l[sol] > l[rmq[logaritm][a + sh]])
        sol = rmq[logaritm][a + sh];
    return h[sol];

}


int main()
{
    int n,m;
    be>>n>>m;
    for(int i=2;i<=n;i++)
    {
        int x;
        be>>x;
        adj[x].push_back(i);
    }
    dfs(1,0);
    rmq1();
    for(int i=1;i<=m;i++){
        int x,y;
        be>>x>>y;
        ki<<lca_function(x,y)<<"\n";
    }
    return 0;
}