#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#define node vecini[x][i]
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out"); ///vector pt prima aparitie,element in tour si adancime
int n,m,h[200005],e[200005],a[22][200005],seen[100005],x,y,ap[100005],H,r,k,rez;
vector<int>vecini[100005];

void dfs(int x)
{
    seen[x]=1;
    e[++k]=x; h[k]=h[k-1]+1;
    if(ap[x]==0) ap[x]=k;
    for(int i=0;i<vecini[x].size();++i)
    {
        if(seen[node]==0)
        {
            dfs(node);
            e[++k]=x;
            h[k]=h[k-1]-1;
        }
    }
}

void RMQ()
{
    H=1;
    for(int j=1;j<=k;++j) a[0][j]=j;
    for(int i=1;(1<<i)<=k;++i)
    {
        r=H; H*=2;
        for(int j=1;j<=k-H+1;++j)
        {
            if(h[a[i-1][j]]<h[a[i-1][j+r]]) a[i][j]=a[i-1][j];
            else a[i][j]=a[i-1][j+r];
        }
    }
}

int main()
{

    f>>n>>m;
    for(int i=2;i<=n;++i)
    {
        f>>x;
        vecini[i].push_back(x);
        vecini[x].push_back(i);
    }
    dfs(1); ///Euler Tour
    RMQ();
    for(int i=1;i<=m;++i)
    {
        f>>x>>y;
        x=ap[x]; y=ap[y]; if(x>y) swap(x,y);
        H=y-x+1;
        r=log2(H);
        H=H-(1<<r);
        if(h[a[r][x]]<h[a[r][x+H]]) rez=e[a[r][x]];
        else rez=e[a[r][x+H]];
        g<<rez<<'\n';
    }
    return 0;
}