#include <bits/stdc++.h>
#define NMAX 100005
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");

vector<int> LA[NMAX];
int lg[2*NMAX+1];
struct varf
{
    int x, lvl;
};

vector<varf> euler;
int n, m;
int first[NMAX], dp[2*NMAX][20];

void dfs(int vf, int pred, int lvl);
void rmq();
int LCA(int x, int y);
void citire();

int main()
{
    int i;
    citire();
    lg[1]=0;
    for (i=2; i<=2*NMAX; i++)
        lg[i]=lg[i/2]+1;

    dfs(1, 0, 0);
    rmq();

    for(i=1; i<=m; ++i)
    {
        int x, y;
        fin>>x>>y;
        fout<<LCA(x, y)<<'\n';
    }
    return 0;
}
void dfs(int vf, int pred, int lvl)
{
    int i, x;
    first[vf] = euler.size();
    euler.push_back({vf, lvl});
    for (i=0; i<LA[vf].size(); i++)
    {
        x=LA[vf][i];
        if(x!=pred)
        {
            dfs(x, vf, lvl + 1);
            euler.push_back({vf, lvl});
        }
    }
}

void rmq()
{
    int i, j, val1, val2;
    int n=euler.size();
    for (i=1; i<=n; i++)
        dp[i][0]=i;
    for (j=1; (1<<j)<=n; j++)
        for (i=1; i<=n-(1<<j)+1; i++)
        {
            val1=dp[i][j-1];
            val2=dp[i+(1<<(j-1))][j-1];
            if (euler[val1].lvl<euler[val2].lvl)
                dp[i][j]=val1;
            else dp[i][j]=val2;
        }
}
int LCA(int x, int y)
{
    x=first[x];
    y=first[y];
    if(x>y)
        swap(x, y);
    int len=y-x+1;
    len=lg[len];
    int val1=dp[x][len], val2=dp[y-(1<<len)+1][len];
    if (euler[val1].lvl<euler[val2].lvl)
        return euler[val1].x;
    return euler[val2].x;
}
void citire()
{
    fin>>n>>m;

    for(int i=2; i<=n; ++i)
    {
        int x;
        fin>>x;
        LA[x].push_back(i);
        LA[i].push_back(x);
    }
}