#include <bits/stdc++.h>

using namespace std;

int niv[100010],first[100010],rmq[19][200010],logg[200010],l;
vector<int> v[100010];

void dfs(int nod,int nivel)
{
    niv[nod]=nivel;
    rmq[0][++l]=nod;
    first[nod]=l;
    for(int i=0;i<v[nod].size();i++)
    {
        dfs(v[nod][i],nivel+1);
        rmq[0][++l]=nod;
    }
}

int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    int n,m,x,y;
    scanf("%d%d",&n,&m);
    for(int i=1;i<n;i++)
    {
        scanf("%d",&x);
        v[x].push_back(i+1);
    }
    dfs(1,0);
    for(int i=2;i<=l;i++) logg[i]=logg[i/2]+1;
    for(int i=1;i<=logg[l];i++)
        for(int j=1;j+(1<<i)-1<=l;j++)
            if(niv[rmq[i-1][j]]<niv[rmq[i-1][j+(1<<(i-1))]]) rmq[i][j]=rmq[i-1][j];
            else rmq[i][j]=rmq[i-1][j+(1<<(i-1))];
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        x=first[x];y=first[y];
        if(x>y) swap(x,y);
        int l1=logg[y-x+1];
        if(niv[rmq[l1][x]]<niv[rmq[l1][y-(1<<l1)+1]]) printf("%d\n",rmq[l1][x]);
        else printf("%d\n",rmq[l1][y-(1<<l1)+1]);
    }
    return 0;
}