#include<bits/stdc++.h>
#define pii pair<int,int>
#define mp make_pair
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");
int const N = 1e5 + 3;
int n , m , sz;
int t[N] , eu[N] , d[N] , from[N];
int dp[2 * N][5 + (int)log2(N)];
vector<int> v[N];
void dfs(int x){
    d[x] = 1 + d[t[x]];
    eu[++ sz] = x;
    if(!from[x])
        from[x] = sz;
    for(auto y : v[x]){
        dfs(y);
        eu[++ sz] = x;
    }
}
int Min(int a , int b){
    return (d[a] < d[b] ? a : b);
}
int main()
{
    fin >> n >> m;
    for(int i = 2 ; i <= n ; ++ i){
        fin >> t[i];
        v[t[i]].push_back(i);
    }
    d[0] = -1;
    dfs(1);
    for(int j = 0 ; (1 << j) <= sz ; ++ j){
        for(int i = (1 << j) ; i <= sz ; ++ i){
            if(j == 0)
                dp[i][j] = eu[i];
            else{
                dp[i][j] = Min(dp[i][j - 1] , dp[i - (1 << (j - 1))][j - 1]);
            }
        }
    }
    for(int i = 1 ; i <= m ; ++ i){
        int a , b;
        fin >> a >> b;
        if(from[a] > from[b])
            swap(a , b);
        a = from[a] , b = from[b];
        int lg = (int)log2(b - a + 1);
        fout << Min(dp[b][lg] , dp[a + (1 << lg) - 1][lg]) << '\n';
    }
    return 0;
}