#include<fstream>
#include<vector>
using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");

#define MAX 200100

int n, m, RMQ[20][MAX];
int euler[MAX], nivel[MAX];

vector<int> array[MAX];

void dfs(int nod){

    int i;
    euler[euler[0]++] = nod;
    nivel[nod] = euler[0];
    for(i = 0; i < (int)array[nod].size(); i++){
        dfs(array[nod][i]);
        euler[euler[0]++] = nod;
    }
}

void rmq(){

    for(int i = 1; i < euler[0]; i++)
        RMQ[0][i] = euler[i];

    for(int i = 1; (1 << i) <= euler[0]; i++)
        for(int j = 1; j<= euler[0] - (1<<i) + 1; j++)
            RMQ[i][j] = min(RMQ[i-1][j], RMQ[i-1][j + (1 << (i-1))]);
}

int query(int a, int b){

    int x, y, i;
    x = nivel[a];
    y = nivel[b];

    if(x > y)
        swap(x, y);
    for(i = 1; (1 << i) <= (y-x+1); i++);
        i--;
    return min(RMQ[i][x], RMQ[i][y - (1 << i) + 1]);
}

int main()
{
    int x, y;
    f>>n>>m;

    for(int i = 2; i <= n; i++){
        f>>x;
        array[x].push_back(i);
    }

    dfs(1);
    rmq();

    for(int i = 1; i <= m; ++i)	{
        f>>x>>y;
        g<<query(x, y)<<"\n";
    }

    f.close();
    g.close();
    return 0;
}