#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>
using namespace std;

int n,m1,nr;
vector<int> m[100010];
bitset<100010> viz;
int dist[200010],x[200010];
int rmq[200010][20];
int apar[100010];
int lg[200010];

void dfs(int nod,int nivel)
{
    nr++;
    dist[nr]=nivel; x[nr]=nod;
    if(!apar[nod]) apar[nod]=nr;
    for(vector<int>::iterator it=m[nod].begin();it!=m[nod].end();it++)
    {
        dfs(*it,nivel+1);
        nr++; dist[nr]=nivel; x[nr]=nod;
    }
}

int minim1(int a,int b)
{
    if(dist[a]<=dist[b]) return a;
    else return b;
}

int main()
{
    int i,j,a,b;
    ifstream t1("lca.in");
    ofstream t2("lca.out");
    t1>>n>>m1;
    for(i=1;i<n;i++)
    {
        t1>>a;
        m[a].push_back(i+1);
    }
    dfs(1,0);

    lg[1]=0;
    for(i=2;i<=nr;i++) lg[i]= lg[i/2]+1;

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

    for(j=1; (1<<j)<=nr; j++)
        for(i=1; i+ (1<<j) -1 <=nr;i++)
            rmq[i][j]=minim1( rmq[i][j-1], rmq[ i + (1<<(j-1)) ][j-1] );

    int l,st,dr;
    for(;m1;m1--)
    {
        t1>>a>>b;
        st=min(apar[b],apar[a]);
        dr=max(apar[a],apar[b]);
        l=lg[ dr - st];
        t2<<x [ minim1( rmq[st][l], rmq[ dr - (1<<l) +1 ][l]  ) ]<<'\n';;
    }

    t1.close();
    t2.close();
    return 0;
}