#include <bits/stdc++.h>

using namespace std;

const int K=18, N=1e5+5;

vector<int> eulerpath;
vector<int> adj[N];

bool vis[N];

int h[N], first[N], lg[2*N], lca[K][2*N];

void dfs(int i, int d){
    eulerpath.push_back(i);
    first[i]=eulerpath.size()-1;
    vis[i]=true;
    h[i]=d;
    for (auto x: adj[i]){
        if (!vis[x]){
            dfs(x, d+1);
            eulerpath.push_back(i);
        }
    }
}

int getlca(int l, int r){
    if (l>r){
        swap(l,r);
    }
    int i=lg[r-l+1];
    int v1=lca[i][l];
    int v2=lca[i][r-(1<<i)+1];
    if (h[v1]<h[v2]){
        return v1;
    }
    else{
        return v2;
    }
}

int main()
{
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdin);
    lg[1]=0;
    for (int i=2;i<2*N;i++){
        lg[i]=lg[i/2]+1;
    }
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    int n,m;cin>>n>>m;
    for (int i=2;i<=n;i++){
        int a;cin>>a;
        adj[a].push_back(i);
    }
    dfs(1, 0);
    n=eulerpath.size();
    for (int i=0;i<n;i++){
        lca[0][i]=eulerpath[i];
    }
    for (int i=1;i<K;i++){
        for (int j=0;j+(1<<i)<=n;j++){
            int v1=lca[i-1][j];
            int v2=lca[i-1][j+(1<<(i-1))];
            if (h[v1]<h[v2]){
                lca[i][j]=v1;
            }
            else{
                lca[i][j]=v2;
            }
        }
    }
    while (m--){
        int u,v;cin>>u>>v;
        u=first[u];
        v=first[v];
        cout<<getlca(u,v)<<'\n';
    }
    return 0;
}