#include <iostream>
#include <fstream>
#include <vector>
#include <cmath>
#define NMAX 100005
#define KMAX 300005
using namespace std;
ifstream fi("lca.in");
ofstream fo("lca.out");
int N, M;
int K = 1;

vector<int> tree[NMAX];
int visited[NMAX];

pair<int, int> sparse[(int)log2(KMAX)][KMAX];

int firstApar[NMAX];



void DFS(int node, int depth)
{
    if(visited[node])
        return;

    visited[node] = 1;

    for(auto y : tree[node])
    {
        DFS(y, depth + 1);
        sparse[0][++K] = {depth, node};
    }
}


void CreateLCASparse()
{
    sparse[0][1] = {0, 1};
    DFS(1, 0);

    for(int i = 1; i < (int) log2(K); ++i)
        for(int j = 1; j < K - (1 << i) + 1; ++j)
            sparse[i][j] = min(sparse[i-1][j], sparse[i-1][j + (1 << (i - 1))]);

    for(int i = 1; i <= K; ++i)
        if(firstApar[sparse[0][i].second] == 0)
            firstApar[sparse[0][i].second] = i;

}

int main()
{
    int a, b;
    fi >> N >> M;
    for(int i = 2; i <= N; ++i)
    {
        fi >> a;
        tree[a].push_back(i);
        tree[i].push_back(a);
    }
    CreateLCASparse();

    for(int i = 1; i <= M; ++i)
    {
        fi >> a >> b;
        int lq = (int) log2(firstApar[b] - firstApar[a] + 1);
        fo << min(sparse[lq][firstApar[a]], sparse[lq][ firstApar[b] -( 1 << lq ) + 1]).second << "\n";
    }


}