#include <fstream>
#include <cmath>
#include <vector>
#include <algorithm> 
using namespace std;

ifstream cin("lca.in");
ofstream cout("lca.out");

vector<int> v[100001];
vector<int> euler; 
vector<int> dp[20]; 
int depths[100001];
int firstPosition[100001];

void dfs(int nod, int val)
{
    depths[nod] = val;
    firstPosition[nod] = euler.size(); 
    euler.push_back(nod);
    
    for(int i = 0; i < v[nod].size(); i++)
    {
        int next = v[nod][i];
        dfs(next, val + 1); 
        euler.push_back(nod); 
    }
}

int FindTheInterval(int a, int b)
{
    int dif = b - a + 1;
    return int(log2(dif)); 
}

void rmq()
{
    int n = euler.size(); 
    
    dp[0].resize(n); 
    for(int i = 0; i < n; i++) 
        dp[0][i] = euler[i]; 
    
    for(int k = 1; (1 << k) <= n; k++) 
    {
        dp[k].resize(n - (1 << k) + 1); 
        for(int i = 0; i + (1 << k) <= n; i++) 
        {
            int left = dp[k-1][i];
            int right = dp[k-1][i + (1 << (k-1))];
            
           
            if(depths[left] < depths[right]) 
                dp[k][i] = left;
            else
                dp[k][i] = right;
        }
    }
}

int queryLCA(int a, int b) 
{
    a = firstPosition[a];
    b = firstPosition[b];
    if(a > b) swap(a, b); 
    
    int len = b - a + 1;
    int k = log2(len); 
    
    int left = dp[k][a];
    int right = dp[k][b - (1 << k) + 1];
    
    if(depths[left] < depths[right]) 
        return left;
    else
        return right;
}

int main()
{
    int n, m;
    cin >> n >> m;
    
    for(int i = 2; i <= n; i++)
    {
        int x;
        cin >> x;
        v[x].push_back(i);
    };
    dfs(1, 0);
    rmq();
    
    for(int i = 1; i <= m; i++)
    {
        int a, b;
        cin >> a >> b;
        cout << queryLCA(a, b) << '\n'; 
    }
    
    return 0; 
}