#include <bits/stdc++.h>
using namespace std;
int dp[22][200000],i,n,nrt,j,k,logy[200005],x,y,nr,first[100005],ll;
vector <int> v[100004];
struct andreea
{
    int niv, node;
}vect[200000];
void dfs(int nod, int lev)
{
    int i;
    nr++;
    vect[nr].node=nod;
    vect[nr].niv=lev;
    first[nod]=nr;
    for(i=0;i<v[nod].size();i++)
    {
        dfs(v[nod][i],lev+1);
        nr++;
        vect[nr].node=nod;
        vect[nr].niv=lev;
    }
}
int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    scanf("%d%d",&n,&nrt);
    for(i=2;i<=n;i++)
    {
        scanf("%d",&x);
        v[x].push_back(i);
    }
    dfs(1,0);
    for(i=2;i<=nr;i++)
        logy[i]=logy[i/2]+1;
    for(i=1;i<=nr;i++)
        dp[0][i]=i;
    for(i=1;(1<<i)<=nr;i++)
    {
        for(j=1;j+(1<<(i-1))<=nr;j++)
        {
            ll=1<<(i-1);
            if(vect[dp[i-1][j]].niv<vect[dp[i-1][j+ll]].niv)dp[i][j]=dp[i-1][j];
            else dp[i][j]=dp[i-1][j+ll];
        }
    }
    for(i=1;i<=nrt;i++)
    {
        scanf("%d%d",&x,&y);
        x=first[x];
        y=first[y];
        if(x>y)swap(x,y);
        k=logy[y-x+1];
        if(vect[dp[k][x]].niv<vect[dp[k][y-(1<<k)+1]].niv)printf("%d\n",vect[dp[k][x]].node);
        else printf("%d\n",vect[dp[k][y-(1<<k)+1]].node);
    }
    return 0;
}