#include <fstream>
#include <vector>

using namespace std;

const int Nmax = 100001;

int n, m, F[Nmax], dp[Nmax][22], depth[Nmax], pow2[22], log2[Nmax];
vector<int> L[Nmax];

void RMQ(){
    for(int i = 1; i <= n; i++){
        for(int j = 1; j <= 20; j++){
            dp[i][j] = dp[dp[i][j-1]][j-1];
        }
    }
}

void dfs(int node){
    for(int son : L[node]){
        depth[son] = depth[node] + 1;
        dfs(son);
    }
}

void preCalc(){
    pow2[0] = 1;
    for(int i = 1; i <= 20; i++){
        pow2[i] = pow2[i-1]*2;
    }
    log2[1] = 0;
    for(int i = 2; i <= Nmax; i++){
        log2[i] = log2[i/2] + 1;
    }
}

int main()
{
    ifstream fin("lca.in");
    ofstream fout("lca.out");
    fin >> n >> m;
    depth[1] = 0;
    for(int i = 2; i <= n; i++){
        int aux;
        fin >> aux;
        dp[i][0] = aux;
        L[aux].push_back(i);
    }

    RMQ();
    dfs(1);
    preCalc();

    for(int j = 1; j <= m; j++){
        int u, v;
        fin >> u >> v;
        if(depth[u] > depth[v]){
            swap(u, v);
        }
        int deficit = depth[v] - depth[u];
        while(deficit > 0){
            int p = log2[deficit];
            v = dp[v][p];
            deficit -= pow2[p];
        }
        if(u == v){
            fout << u << "\n";
        }
        else{
            for(int i = 20; i >= 0; i--){
                if(dp[u][i] != dp[v][i]){
                    u = dp[u][i];
                    v = dp[v][i];
                }
            }
            u = dp[u][0];
            v = dp[v][0];
            fout << u << "\n";
        }
    }

    return 0;
}