#include <fstream>
#include <vector>
#include <cmath>
using namespace std;
ifstream cin("lca.in");
ofstream cout("lca.out");

const int n_max=100001;
const int log_n_max=17;

int n, q, i, x, y, k, nivel[n_max], e[2*n_max+4], lvl[2*n_max+4], p[n_max], rm[log_n_max][n_max];
vector<int> a[n_max];

void mark(int nod)
{
    e[++k]=nod;
    lvl[k]=nivel[nod];
    p[nod]=k;
}

void dfs(int nod)
{
    int i;
    mark(nod);
    for(i=0; i<a[nod].size(); i++)
        {
            dfs(a[nod][i]);
            mark(nod);
        }
}

void rmq(int v[], int n)
{
    int i, j;
    for(j=1; j<=n; j++)
        rm[0][j]=j;
    for(i=1; (1<<i)<n; i++)
        for(j=1; j+(1<<i)-1<=n; j++)
            if(v[rm[i-1][j]] < v[rm[i-1][j+(1<<(i-1))]])
                rm[i][j]=rm[i-1][j];
            else
                rm[i][j]=rm[i-1][j+(1<<(i-1))];
}

int query(int v[], int x, int y)
{
    int k=log2(y-x+1);
    if(v[rm[k][x]] < v[rm[k][y-(1<<k)+1]])
        return rm[k][x];
    return rm[k][y-(1<<k)+1];
}

int main()
{
    cin>>n>>q;
    for(i=2; i<=n; i++)
    {
        cin>>x;
        a[x].push_back(i);
        nivel[i]=nivel[x]+1;
    }
    dfs(1);
    rmq(lvl, k);
    while(q--)
    {
        cin>>x>>y;
        if(p[x]>p[y]) swap(x, y);
        cout<<e[query(lvl ,p[x], p[y])]<<'\n';
    }
    return 0;
}