#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#define N 100005
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int h[N],l[2*N],e[2*N],n,m,tati[N],a[2*N][20],k,seen[N],r,H,x,y,rez;
vector<int> vecini[N];

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

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

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