#include <fstream>
#include <vector>
#include <math.h>

#define pb push_back

using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");

int n, q, parent[100005], first[100005], v[210005], depth[210005], rmq[210005][20];
vector<int> a[100005];

void DFS(int nod, int adanc) {
    v[++v[0]] = nod;
    depth[v[0]] = adanc;

    for(int i=0; i<a[nod].size(); i++) {
        DFS(a[nod][i], adanc + 1);
        v[++v[0]] = nod;
        depth[v[0]] = adanc;
    }
}

int pwr(int a) {
    int pw = 1, exp = 0;
    while(pw <= a) {
        pw *= 2;
        exp++;
    }

    return exp-1;
}

int get_min(int x, int y) {
    int lg = pwr(y-x+1);

    if(depth[rmq[x][lg]] < depth[rmq[y-(1<<lg)+1][lg]])
        return v[rmq[x][lg]];
    else return v[rmq[y-(1<<lg)+1][lg]];
}

int lca(int x, int y) {
    int frstx = first[x];
    int frsty = first[y];

    return get_min(min(frstx, frsty), max(frstx, frsty));
}

int main()
{
    in >> n >> q;
    for(int i=2; i<=n; i++) {
        int x;
        in >> x;
        parent[i] = x;
        a[x].pb(i);
    }

    DFS(1, 1);

    /*for(int i=1; i<=v[0]; i++)
        out << depth[i] << ' ';
    out << '\n';
    for(int i=1; i<=v[0]; i++)
        out << v[i] << ' ';
    out << '\n';*/

    for(int i=1; i<=v[0]; i++)
        if(!first[v[i]])
            first[v[i]] = i;

    for(int j=0; (1<<j)<=v[0]; j++)
        for(int i=1; i+(1<<j)-1<=v[0]; i++) {
            if(!j)
                rmq[i][j] = i;
            else {
                if(depth[rmq[i][j-1]] < depth[rmq[i+(1<<(j-1))][j-1]])
                    rmq[i][j] = rmq[i][j-1];
                else rmq[i][j] = rmq[i+(1<<(j-1))][j-1];
            }
        }

    while(q--) {
        int x, y;
        in >> x >> y;
        out << lca(x, y) << '\n';
    }
    return 0;
}