#include <stdio.h>
#include <vector>
#include <cmath>
std::vector<int> adj[100001];
int pos,ap[100001],ni[100001],niv[500001],fin[500001],n;
int rmq[500001][20];
int p[20];
void dfs(int nod)
{
    fin[pos]=nod;
    ap[nod] = pos;
    pos++;
    std::vector<int>::iterator it;
    for(it=adj[nod].begin();it!=adj[nod].end();++it)
    {
        dfs(*it);
        fin[pos]=nod;
        pos++;
    }
}
int minim(int a,int b)
{
    if(a>b)return b;
    return a;
}
int main()
{
    freopen ("lca.in","r",stdin);
    freopen ("lca.out","w",stdout);
    int m;
    scanf("%d%d",&n,&m);
    int nr;
    niv[1]=1;
    for(int i=2;i<=n;i++)
    {
        scanf("%d",&nr);
        adj[nr].push_back(i);
        ni[i]=ni[nr]+1;
    }
    pos=1;
    dfs(1);
    for(int i = 1; i <=pos; ++i) niv[i]=ni[fin[i]];
    //for(int i=1;i<=pos;i++) printf("%d ",niv[i]);
    //printf("\n");
    pos--;
    for(int i=1;i<=pos;i++) rmq[i][0]=i;
    for(int j=1;(1<<j)<=pos;j++)
    {
        for(int i=1;i+(1<<j)-1<=pos;i++)
        {
            if(niv[rmq[i][j-1]]<niv[rmq[i+(1<<(j-1))][j-1]]) rmq[i][j]=rmq[i][j-1];
            else rmq[i][j]=rmq[i+(1<<(j-1))][j-1];
        }
    }
    int x,y;
    int temp;
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        x=ap[x];
        y=ap[y];
        if(x>y)
        {
            temp=x;
            x=y;
            y=temp;
        }
        int k=log2(y-x+1);
        if(niv[rmq[x][k]]<niv[rmq[y-(1<<k)+1][k]]) printf("%d\n",fin[rmq[x][k]]);
        else printf("%d\n",fin[rmq[y-(1<<k)+1][k]]);
    }
}