#include <cstdio>
#include <vector>
#include <algorithm>
using namespace std;
const int NMAX = 200105;
vector <int> vec[NMAX];
int he[NMAX];
int e[NMAX];
int poz[NMAX];
bool viz[NMAX];
int top = 0;
void dfs(int u, int height) {
    viz[u] = 1;
    for(int v : vec[u]) {
        if(viz[v] == 0) {
            he[++top] = height;
            if(poz[u] == 0) {
                poz[u] = top;
            }
            e[top] = u;
            dfs(v, height + 1);
        }
    }
    he[++top] = height;
    if(poz[u] == 0) {
        poz[u] = top;
    }
    e[top] = u;
}
int rmq[NMAX][30];
int rmqpoz[NMAX][30];
int p2[30];
int nr2[NMAX];

int main() {
    int n, m;
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    scanf("%d%d", &n, &m);
    for(int i = 2; i <= n; i++) {
        int f;
        scanf("%d", &f);
        vec[i].push_back(f);
        vec[f].push_back(i);
    }
    dfs(1, 0);
    int put = 0, put2 = 1;
    for(int i = 1; i <= top; i++) {
        if(i >= put2 * 2) {
            put2 *= 2;
            put++;
        }
        rmq[i][0] = he[i];
        rmqpoz[i][0] = e[i];
        nr2[i] = put2;
        p2[i] = put;
    }
    for(int l = 1, j = 1; l <= top; j++, l *= 2) {
        for(int i = 1; i <= top - l; i++) {
            if(rmq[i][j - 1] < rmq[i + l][j - 1]) {
                rmq[i][j] = rmq[i][j - 1];
                rmqpoz[i][j] = rmqpoz[i][j - 1];
            }
            else {
                rmq[i][j] = rmq[i + l][j - 1];
                rmqpoz[i][j] = rmqpoz[i + l][j - 1];
            }
        }
    }
    for(int i = 1; i <= m; i++) {
        int a, b;
        scanf("%d %d", &a, &b);
        int poza = min(poz[a], poz[b]);
        int pozb = max(poz[a], poz[b]);
        int dist = pozb - poza + 1;
        int n1 = rmq[poza][p2[dist]];
        int n2 = rmq[pozb - nr2[dist] + 1][p2[dist]];
        if(n1 < n2) {
            printf("%d\n", rmqpoz[poza][p2[dist]]);
        }
        else {
            printf("%d\n", rmqpoz[pozb - nr2[dist] + 1][p2[dist]]);
        }
    }
    return 0;
}