#include <fstream>
#include <vector>
#include <algorithm>
using namespace std;
ifstream cin("lca.in");
ofstream cout("lca.out");
int n,m,x, lg[400005], first[100005];
vector<int> v[100005];
vector<pair<int,int>> euler;
pair<int,int> rmq[400005][20];
void dfs(int nod, int niv){
    euler.push_back({niv,nod});
    if(first[nod]==-1)
        first[nod]=euler.size()-1;
    for(auto neigh: v[nod]){
        dfs(neigh, niv+1);
        euler.push_back({niv, nod});
    }
}
int query(int a, int b){
    int l=lg[b-a+1];
    return min(rmq[a][l], rmq[b-(1<<l)+1][l]).second;
}
int main()
{
    cin>>n>>m;
    for(int i=2; i<=n;i++){
        cin>>x;
        v[x].push_back(i);
    }
    for(int i=1; i<=n;i++)
        first[i]=-1;
    dfs(1,1);
    int indx=0;
    for(auto u: euler){
        rmq[indx][0]=u;
        indx++;
    }
    int ne=euler.size()-1;
    for(int i=2; i<=ne;i++){
        lg[i]=lg[i-1];
        if(!(i&(i-1))) lg[i]++;
    }
    for(int j=1; (1<<j)<=ne; j++)
        for(int i=0; i+(1<<j)-1<=ne; i++)
            rmq[i][j]=min(rmq[i][j-1], rmq[i+(1<<(j-1))][j-1]);
    int a,b;
    while(m--){
        cin>>a>>b;
        a=first[a];
        b=first[b];
        if(a>b) swap(a,b);
        cout<<query(a, b)<<'\n';
    }
    return 0;
}