#include <iostream>
#include <cstdio>
#include <vector>
#include <algorithm>
#include <cmath>

using namespace std;

int n,m,x,y;
vector <int> g[100005];
int d[100005], ap[100005];
vector <int> dp[20];

void dfs(int nod, int ad){
    d[nod] = ad;
    ap[nod]=dp[0].size();
    dp[0].push_back(nod);

    for(int i : g[nod]){
        dfs(i,ad+1);
        dp[0].push_back(nod);
    }

}

int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);

    scanf("%d%d", &n,&m);

    for(int i=2;i<=n;++i){
        scanf("%d", &x);
        g[x].push_back(i);
    }

    dfs(1,0);

    int ln = dp[0].size();

    for(int i = 1; (1<<i)<=ln;++i){
        for(int j = 0; j+(1<<(i-1))<ln;++j)
            if(d[dp[i-1][j]]<d[dp[i-1][j+(1<<(i-1))]])
                dp[i].push_back(dp[i-1][j]);
            else
                dp[i].push_back(dp[i-1][j+(1<<(i-1))]);
    }

    for(int i = 0; i < m; ++i){
        scanf("%d%d", &x,&y);
        x=ap[x];
        y=ap[y];
        if(x>y)
            swap(x,y);
        int k = log2(y-x+1);
        if(d[dp[k][x]]<d[dp[k][y-(1<<(k))+1]])
            cout<<dp[k][x];
        else
            cout<<dp[k][y-(1<<(k))+1];
        cout<<"\n";
    }

    return 0;
}