#include<cstdio>
#include<vector>
using namespace std;
const int NMAX = 100000;
vector <int> v[NMAX + 2];
bool viz[NMAX + 2];
struct euler
{
    int nod, h;
};
euler p[2 * NMAX + 2];
int rmq[2 * NMAX + 2][20];
int log2[2 * NMAX + 2];
int poz[2 * NMAX + 2];
int nr;
void dfs(int node, int lvl)
{
    int ok = 0;
    viz[node] = true;
    p[++nr].nod = node;
    p[nr].h = lvl;
    poz[node] = nr;
    int size = v[node].size();
    for(int i = 0; i < size; i++)
        if(!viz[v[node][i]])
        {
            dfs(v[node][i], lvl + 1);
            p[++nr].nod = node;
            p[nr].h = lvl;
        }
}
int main()
{
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    int n, m, f, i, j, a, b;
    scanf("%d%d", &n, &m);
    for(i = 2; i <= n; i++)
    {
        scanf("%d", &f);
        v[f].push_back(i);
    }
    dfs(1, 0);
    for(i = 2; i < nr; i++)
        log2[i] = log2[i / 2] + 1;
    for(i = 1; i <= nr; i++)
        rmq[i][0] = i;

    for(j = 1; (1<<j) <= nr; j++)
        for(i = 1; i + (1<<j) - 1 <= nr; i++)
            if(p[rmq[i][j -1]].h < p[rmq[i + (1 << (j - 1))][j - 1]].h)
                rmq[i][j] = rmq[i][j-1];
            else
                rmq[i][j] = rmq[i + (1<<(j-1))][j-1];

    for(i = 1; i <= m; i++)
    {
        scanf("%d%d", &a, &b);
        a = poz[a];
        b = poz[b];
        if(a > b)
            swap(a, b);
        int k = log2[b - a + 1];
        if(p[rmq[a][k]].h <= p[rmq[b - (1<<k) + 1][k]].h)
            printf("%d\n", p[rmq[a][k]].nod);
        else
            printf("%d\n", p[rmq[b - (1<<k) + 1][k]].nod);
    }
    return 0;
}