#include <bits/stdc++.h>
using namespace std;
const int MAXN = 1e5 + 50;
const int LOGMAX = 20 + 4;
ifstream fin("lca.in");
ofstream fout("lca.out");
vector <int> g[MAXN];
int father[LOGMAX][MAXN];
int dist[MAXN];
void dfs(int node, int papa){
    dist[node] = dist[papa] + 1;
    for(auto x : g[node]){
        if(x != papa) dfs(x, node);
    }
}
void rezolvare(int x, int y){
    for(int i = LOGMAX - 4; i >= 0; --i){
        if(father[i][x]  !=  father[i][y])
            x = father[i][x], y = father[i][y];
    }
    fout << father[0][x] << '\n';
}
void initializare(int n){
    for(int x = 1; x <= LOGMAX - 4; ++x)
        for(int i = 1; i <= n; ++i)
            father[x][i] = father[x - 1][father[x - 1][i]];
}
int main() /// REZ O(N * log(N) + M * log(M))
{
    ios::sync_with_stdio(false);
    fin.tie(0); fout.tie(0);
    int n, m; fin >> n >> m;
    for(int i = 1; i < n; ++i){
        int x ; fin >> x;
        g[x].push_back(i + 1);
        father[0][i + 1] = x;
    }
    dfs(1, 0);
    //for(int i = 1; i <= n; ++i) fout << dist[i] << " ";
    for(int i = 1; i <= m; ++i){
        int x, y; fin >> x >> y;
        if(dist[y] > dist[x]) swap(x, y);
        int nivel = dist[x] - dist[y] ;
        for(int i = 0; (1 << i) <= nivel; ++i)
            if(nivel & (1 << i)) x = father[i][x];
        if(x != y) rezolvare(x ,y);
        else fout << x << '\n';
    }
    return 0;
}