#include <fstream>
#include <vector>
#include <cmath>

using namespace std;
ifstream in("lca.in");
ofstream out("lca.out");

const int nmax = 1e5;
vector<int>g[nmax + 1];
int nivel[nmax + 1];
int n;
int stramosi[18][2*nmax + 1];

void dfs(int node,int lvl)
{
    nivel[node] = lvl;
    lvl++;
    for(int i = 0; i < g[node].size(); i++)
    {
        int vecin = g[node][i];
        if(nivel[vecin] == 0)
            dfs(vecin,lvl);
    }
}
void build_stramosi()
{
    int l2 = log2(n);
    for(int i = 1; i <= l2; i++)
        for(int j = 1; j <= n; j++)
            stramosi[i][j] = stramosi[i - 1][stramosi[i - 1][j]];
}
int equalize(int node, int down)
{
    int l2 = log2(n);
    for(int i = l2; i >= 0; i--)
        if(stramosi[i][node] != 0 && (1<<i) <= down && nivel[node] - 1 >= (1<<i))
        {
            node = stramosi[i][node];
            down -= (1<<i);
        }
    return node;
}
void findstramos(int x,int y)
{
    if(x == y)
        out<<x<<'\n';
    else
    {
        int l2 = log2(n);
        for(int i = l2; i >= 0; i--)
        {
            if(stramosi[i][x] != stramosi[i][y])
            {
                x = stramosi[i][x];
                y = stramosi[i][y];
            }
        }
        out<<stramosi[0][x]<<'\n';
    }
}
int main()
{
    int m;
    in>>n>>m;
    for(int i = 2; i <= n; i++)
    {
        in>>stramosi[0][i];
        g[stramosi[0][i]].push_back(i);
    }
    dfs(1,1);
    build_stramosi();
    for(int i = 1; i <= m; i++)
    {
        int x,y;
        in>>x>>y;
        if(nivel[x] != nivel[y])
        {
            if(nivel[x] < nivel[y])
            {
                int down = nivel[y] - nivel[x];
                int copil = equalize(y, down);
                findstramos(copil,x);
            }
            else if(nivel[x] > nivel[y])
            {
                int down = nivel[x] - nivel[y];
                int copil = equalize(x,down);
                findstramos(copil,y);
            }
        }
        else
            findstramos(x,y);
    }
    return 0;
}