#include <bits/stdc++.h>

using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");

int n,m,h;
pair <int,int> rmq[30][300005];
vector <int> V[100005];
int fnd[100005];
void dfs(int x,int lvl)
{
    rmq[0][++h].first=x;
    rmq[0][h].second=lvl;
    fnd[x]=h;
    for(int i=0; i<V[x].size(); i++)
    {
        dfs(V[x][i],lvl+1);
        rmq[0][++h].first=x;
        rmq[0][h].second=lvl;
    }
}
int main()
{
    f>>n>>m;
    for(int i=2; i<=n; i++)
    {
        int x;
        f>>x;
        V[x].push_back(i);
    }
    dfs(1,0);
    for(int i=1; i<=(int)log2(h); i++)
        for(int j=1; j<=h-(1<<(i-1)); j++)
            if(rmq[i-1][j].second<rmq[i-1][j+(1<<(i-1))].second)
                rmq[i][j]=rmq[i-1][j];
            else
                rmq[i][j]=rmq[i-1][j+(1<<(i-1))];

    while(m--)
    {
        int x,y;
        f>>x>>y;
        int x1=fnd[x];
        int y1=fnd[y];
        if(x1>y1)
            swap(y1,x1);
        int k=log2(y1-x1+1);
        if(rmq[k][x1].second>rmq[k][y1-(1<<k)+1].second)
            g<<rmq[k][y1-(1<<k)+1].first<<'\n';
        else
            g<<rmq[k][x1].first<<'\n';
    }



    return 0;
}