#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");
int n,m,a1,dp[100005],log[600005],x,y;
int rmq[25][200005];
int ap[100005];
vector<int> v[100005];
vector <int> s;
void dfs(int nod)
{
    s.push_back(nod);
    if(ap[nod]==0)ap[nod]=s.size()-1;
    for(auto i:v[nod])
    {
        dfs(i);
        s.push_back(nod);
    }
}
int main()
{
    in>>n>>m;
    for(int i=2;i<=n;i++)
    {
        in>>a1;
        v[a1].push_back(i);
        dp[i]=dp[a1]+1;
    }
    dfs(1);
    n=s.size();
    for(int i=0;i<n;i++)
    {
        rmq[0][i]=s[i];
    }
    for(int i=2;i<=(1<<19);i++)
    {
        log[i]=log[i/2]+1;
    }
    for(int i=1;i<=19;i++)
    {
        for(int j=0;j<=(n-(1<<i));j++)
        {
            if(dp[rmq[i-1][j]]<dp[rmq[i-1][j+(1<<(i-1))]])
            {
                rmq[i][j]=rmq[i-1][j];
            }
            else
            {
                rmq[i][j]=rmq[i-1][j+(1<<(i-1))];
            }
        }
    }
    int aux,minim,add,aux2;
    for(int i=1;i<=m;i++)
    {
        aux2=0x3f3f3f3f;
        in>>x>>y;
        x=ap[x],y=ap[y];
        if(x>y)swap(x,y);
        aux=(y-x+1);
        add=(1<<log[aux]);
        while(x<=y)
        {
            if(aux2>dp[rmq[log[aux]][x]])
            {
                minim=rmq[log[aux]][x];
                aux2=dp[minim];
            }

            x+=add;
            aux=(y-x+1);
            add=(1<<log[aux]);
        }
        out<<minim<<'\n';
    }
    return 0;
}