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

#define NMAX 100005
#define LMAX 20

ifstream fin("lca.in");
ofstream fout("lca.out");

int k, n, Q, a, b;
int level[NMAX << 1], euler[NMAX << 1],p2[NMAX << 1], fst[NMAX];
int rmq[LMAX][NMAX << 2]; ///rmq[i][j] = nod de nivel minim din pozitiile (j, j + 2^i - 1) din euler
vector <int> G[NMAX];
 
void dfs(int nod, int nivel) {
    euler[++k] = nod;
    level[k] = nivel;
    fst[nod] = k;
    
    for (auto it: G[nod]) {
        dfs(it, nivel+1);
        euler[++k] = nod;
        level[k] = nivel;
    }
    
}

int lca(int x, int y) {
    int a = fst[x], b = fst[y];
    if (a > b) swap(a, b);
    
    int diff = b-a+1;
    int L = p2[diff];
    int sol = rmq[L][a];
    int dr = b+1 - (1<<L);
    
    if (level[sol] > level[rmq[L][dr]]) { ///am gasit un nod cu un nivel mai sus
        sol = rmq[L][dr];
    }
    return euler[sol];
}

int main() {
    
    fin >> n >> Q;
    for (int i = 2; i<=n; i++) {
        fin >> a;
        G[a].push_back(i);
    }
    
    dfs(1, 0);
    
    for (int i = 2; i<=k; i++) {
        p2[i] = p2[i/2]+1;
    }
    
    for (int i = 1; i<=k; i++) {
        rmq[0][i] = i;
    }
    
    for (int i = 1; (1<<i) < k; i++) {
        for (int j = 1; j<=k-(1<<i); j++) {
            rmq[i][j] = rmq[i-1][j];
            int L = (1<<(i-1));
            if (level[rmq[i-1][j+L]] < level[rmq[i][j]]) {
                rmq[i][j] = rmq[i-1][j+L];
            }    
        }
    }
    
    while (Q--) {
        fin >> a >> b;
        fout << lca(a, b) << "\n";
    }
    
    return 0;
}