#include <bits/stdc++.h>
#define N 100005
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
int n,m,rmq[21][N],e[N],niv[N],p,poz[N];
vector<int>g[N];
void Euler(int x,int nivel)
{
    e[++p]=x;
    niv[p]=nivel;
    poz[x]=p;
    for(int i:g[x])
    {
        Euler(i,nivel+1);
        e[++p]=x;
        niv[p]=nivel;
    }
}
int main()
{
    int i,j,x,y;
    fin>>n>>m;
    for(i=2;i<=n;i++)
        fin>>x,g[x].push_back(i);
    Euler(1,1);
    for(i=1;i<=p;i++) rmq[0][i]=i;
    for(j=1;j<=log2(p);j++)
        for(i=1;i+(1<<j)-1<=p;i++)
          rmq[j][i]=(niv[rmq[j-1][i]]<niv[rmq[j-1][i+(1<<(j-1))]]?rmq[j-1][i]:rmq[j-1][i+(1<<(j-1))]);///min(rmq[j-1][i],rmq[j-1][i+1<<(j-1)]);
    ///for(i=1;i<=p;i++) cout<<e[i]<<" ";cout<<"\n";
    ///for(i=1;i<=p;i++) cout<<niv[i]<<" ";cout<<"\n";
    while(m--)
    {
        fin>>x>>y;
        x=poz[x];y=poz[y];
       /// cout<<x<<" "<<y<<"\n";
        if(x>y) swap(x,y);
        int lg=log2(y-x+1);
        fout<<(niv[rmq[lg][x]]<niv[rmq[lg][y-(1<<lg)+1]]?e[rmq[lg][x]]:e[rmq[lg][y-(1<<lg)+1]])<<"\n";
    }
    return 0;
}