#include <bits/stdc++.h>

using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
int n,m,x,y;
int ap[100005],mn[22][200005];
vector<int>nod[100005],line,val;
void go_visit(int pos,int length)
{
    line.push_back(pos);
    val.push_back(length);
    ap[pos]=line.size()-1;
    for(int i=0;i<nod[pos].size();i++)
    {
        go_visit(nod[pos][i],length+1);
        line.push_back(pos);
        val.push_back(length);
    }
}
void rmq()
{
    for(int i=1;(1<<i)<=n+1;i++)
        for(int j=0;j<=n-(1<<i);j++)
            if(val[mn[i-1][j]]<val[mn[i-1][j+(1<<(i-1))]])
               mn[i][j]=mn[i-1][j];
            else
                mn[i][j]=mn[i-1][j+(1<<(i-1))];
}
int main()
{
    fin>>n>>m;
    for(int i=2;i<=n;i++)
    {
        fin>>x;
        nod[x].push_back(i);
    }
    go_visit(1,1);
    n=line.size();
    for(int i=0;i<n;i++)
        mn[0][i]=i;
    rmq();
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        x=ap[x];
        y=ap[y];
        if(x>y)
            swap(x,y);
        int j=0;
        while((1<<(j+1))<=y-x+1)
            j++;
        if(y==1<<j)
        {
            fout<<line[mn[j][x]]<<"\n";
            continue;
        }
        int p2=y-(1<<j)+1;
        if(val[mn[j][x]]<val[mn[j][p2]])
            fout<<line[mn[j][x]];
        else
            fout<<line[mn[j][p2]];
        fout<<"\n";
    }
    return 0;
}