#include <bits/stdc++.h>

using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
vector <int> v[100001];
int n,m,k,euler[200002],apar[100001],h[100001],d[200002][20],q;
void dfs(int x)
{
    euler[++k]=x;
    apar[x]=k;
    for(int i:v[x])
    {
        if(h[i]==0)
        {
            h[i]=h[x]+1;
        }
        dfs(i);
        euler[++k]=x;
    }
}
int main()
{
    int x,y;
    fin>>n>>m;
    for(int i=2; i<=n; i++)
    {
        fin>>x;
        v[x].push_back(i);
    }
    dfs(1);
    for(int i=1; i<=k; i++)d[i][0]=euler[i];
    for(int j=1; (1<<j)<=k; j++)
    {
        for(int i=1; i+(1<<j)-1<=k; i++)
        {
            if(h[d[i][j-1]]<h[d[i+(1<<(j-1))][j-1]]) d[i][j]=d[i][j-1];
            else d[i][j]=d[i+(1<<(j-1))][j-1];
        }
    }
    for(int i=1; i<=m; i++)
    {
        fin>>x>>y;
        x=apar[x];
        y=apar[y];
        if(x>y)swap(x,y);
        q=log2(y-x+1);
        if(h[d[x][q]]<h[d[y-(1<<q)+1][q]])fout<<d[x][q];
        else fout<<d[y-(1<<q)+1][q];
        fout<<'\n';
    }
    return 0;
}