#include<iostream>
#include<fstream>
#include<algorithm>
#include<vector>
using namespace std;
const int NMAX=200005;

ifstream si("lca.in");
ofstream so("lca.out");

vector<int> v[NMAX];
int eu [2*NMAX],niv[2*NMAX],pa[NMAX],l[NMAX];
int sol[20][4*NMAX];

int k;

void dfs(int nod, int n) {
    eu[++k]=nod;
    niv[k]=n;
    pa[nod]=k;
    for(vector<int>::iterator i=v[nod].begin(); i!=v[nod].end(); ++i) {
        dfs(*i,n+1);
        eu[++k]=nod;
        niv[k]=n;
    }
}
int main() {
    int n, m;
    si>>n>>m;
    int a;
    for(int i=2; i<=n; ++i) {
        si>>a;
        v[a].push_back(i);
    }
    dfs(1, 0);
    for(int i=2; i<=k; ++i)
        l[i]=l[i/2]+1;
    for(int i=1; i<=k; ++i)
        sol[0][i]=i;
    a=2;
    for(int i=1; a<=k; ++i, a<<=1)
    {
        int b;
        b=k-a+1;
        for(int j=1; j<=b; ++j) {
            if(niv[sol[i-1][j]] < niv[sol[i-1][j+(a>>1)]])
                sol[i][j]=sol[i-1][j];
            else
                sol[i][j]=sol[i-1][j+(a>>1)];
        }
    }
    int x, val;
    for(int i=0; i<m; ++i) {
        int b;
        si>>a>>b;
        a=pa[a];
        b=pa[b];
        if(a > b)
            swap(a,b);
        x=l[b-a+1];
        if(niv[sol[x][a]] < niv[sol[x][b-(1<<x)+1]])
            val=sol[x][a];
        else
            val=sol[x][b-(1<<x)+1];
        so<<eu[val]<<'\n';
    }
    return 0;
}