#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#define node vecini[x][i]
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int n,m,e[200005],h[200005],p[200005],rez;
int a[25][200005],seen[200005],x,y,k,H,r;
vector<int> vecini[200005];

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

void RMQ()
{
    for(int i=1;i<=k;++i) a[0][i]=i;
    for(int i=1;(1<<i)<=k;++i)
    {
        H=(1<<i); r=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(1,0); ///euler tour
    RMQ();
    for(int i=1;i<=m;++i)
    {
        f>>x>>y; x=p[x]; y=p[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=a[r][x];
        else rez=a[r][x+H];
        g<<e[rez]<<'\n';
    }
    return 0;
}