#include<stdio.h>
#include<vector>
#define NMAX 200005
using namespace std;
int n,m,x,k;
vector<int> v[NMAX];
int euler [2*NMAX],nivel[2*NMAX],primaap[NMAX],Lg[NMAX];
int rmq[20][4*NMAX];
void dfs(int nod,int niv)
{
    euler[++k]=nod;
    nivel[k]=niv;
    primaap[nod]=k;
    for(vector<int>::iterator i=v[nod].begin(); i!=v[nod].end(); ++i)
    {
        dfs(*i,niv+1);
        euler[++k]=nod;
        nivel[k]=niv;
    }
}
void rm()
{
    for(int i = 2; i <= k; ++i)
        Lg[i] = Lg[i >> 1] + 1;
    for(int i = 1; i <= k; ++i)
        rmq[0][i] = i;

    for(int i = 1; (1 << i) < k; ++i)
        for(int j = 1; j <= k - (1 << i); ++j)
        {
            int l = 1 << (i - 1);

            rmq[i][j] = rmq[i-1][j];
            if(nivel[rmq[i-1][j + l]] < nivel[rmq[i][j]])
                rmq[i][j] = rmq[i-1][j + l];
        }
}
int lca(int x, int y)
{
    int diff, l, sol, sh;
    int a = primaap[x], b = primaap[y];
    if(a > b) swap(a, b);
    diff = b - a + 1;
    l = Lg[diff];
    sol = rmq[l][a];
    sh = diff - (1 << l);
    if(nivel[sol] > nivel[rmq[l][a + sh]])
        sol = rmq[l][a + sh];
    printf("%d\n",euler[sol]);
}
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);
        v[x].push_back(i);
    }
    dfs(1,0);
    rm();
    for(int lol=1; lol<=m; lol++)
    {
        int x,y;
        scanf("%d %d",&x,&y);
        lca(x,y);
    }
}