#include <stdio.h>
#include <vector>
using namespace std;
int n,m,i,e[200001],nr,t,f[100001],niv[100001],x,y,r[200001][20],lg[200001];
bool o[100001];
vector<int> G[100001];
void DFS(int s)
{
    int i,z=G[s].size();
    o[s]=1;
    e[++nr]=s; f[s]=nr;
    for (i=0;i<z;i++)
        if (!o[G[s][i]])
    {
        niv[G[s][i]]=niv[s]+1;
        DFS(G[s][i]);
        e[++nr]=s;
    }
}
void init()
{
    int i;
    scanf("%i%i",&n,&m);
    for (i=2;i<=n;i++)
    {
        scanf("%i",&t);
        G[t].push_back(i);
        G[i].push_back(t);
    }
    DFS(1);
}
void rmq()
{
    int i,j,p=1;
    for (i=1;i<=nr;i++) r[i][0]=e[i];
    for (j=1;p<=nr;j++,p<<=1)
        for (i=1;i<=nr-p+1;i++)
        if (niv[r[i][j-1]]<niv[r[i+p][j-1]])
            r[i][j]=r[i][j-1];
        else r[i][j]=r[i+p][j-1];
    j=1; p=1;
    for (i=-1;j<=nr;j++)
    {
        if (j==p) i++,p<<=1;
        lg[j]=i;
    }
}
int lca(int a,int b)
{
    int l=lg[b-a+1];
    if (niv[r[a][l]]<niv[r[b-(1<<l)+1][l]])
        return r[a][l];
    return r[b-(1<<l)+1][l];
}
int main()
{
    freopen ("lca.in","r",stdin);
    freopen ("lca.out","w",stdout);
    init();
    rmq();
    while (m--)
    {
        scanf("%i%i",&x,&y);
        printf("%i\n",lca(min(f[x],f[y]),max(f[x],f[y])));
    }
    fclose(stdin);
    fclose(stdout);
    return 0;
}