#include <bits/stdc++.h>

using namespace std;

vector <int> v[100055];

int d[300055],nd[300055];

int in;

int frst[300055];

void dfs(int k,int i)
{
    ++in;
    d[in]=i;
    nd[in]=k;
    for(auto a:v[k])
    {
        dfs(a,i+1);
        ++in;
        d[in]=i;
        nd[in]=k;
    }
}

int p[45];

int rmq[45][300005];

int main()
{
    ifstream cin("lca.in");
    ofstream cout("lca.out");
    int n,m,x,nde;
    cin>>n>>m;
    for(int i=2;i<=n;++i)
    {
        cin>>x;
        if(x!=i)
        {
            v[x].push_back(i);
        }
    }
    dfs(1,1);
    for(int i=1;i<=in;++i)
    {
        if(frst[nd[i]]==0)
        {
            frst[nd[i]]=i;
        }
    }
    p[0]=1;
    for(int i=1;i<=20;++i)
    {
        p[i]=p[i-1]*2;
    }
    for(int i=1;i<=in;++i)
    {
        rmq[0][i]=i;
    }
    for(int pp=1;pp<=20;++pp)
    {
        for(int i=1;i<=in-p[pp]+1;++i)
        {
           // rmq[pp][i]=min(rmq[pp-1][i])
            if(d[rmq[pp-1][i]]<=d[rmq[pp-1][i+p[pp-1]]])
            {
                rmq[pp][i]=rmq[pp-1][i];
            }
            else
            {
                rmq[pp][i]=rmq[pp-1][i+p[pp-1]];
            }
        }
    }
    int a,b;
    for(int i=1;i<=m;++i)
    {
        cin>>a>>b;
        int aa,bb;
        aa=min(frst[a],frst[b]);
        bb=max(frst[a],frst[b]);
        int l=bb-aa+1;
        int st=0,dr=20,mij,in;
        while(st<=dr)
        {
            mij=(st+dr)/2;
            if(p[mij]<=l)
            {
                in=mij;
                st=mij+1;
            }
            else
            {
                dr=mij-1;
            }
        }
             if(d[rmq[in][aa]]<=d[rmq[in][bb-p[in]+1]])
            {
                cout<<nd[rmq[in][aa]]<<"\n";
            }
            else
            {
                cout<<nd[rmq[in][bb-p[in]+1]]<<"\n";
            }
    }
    return 0;
}