#include <bits/stdc++.h>

using namespace std;

vector <int> v[100555];

int p[25];

int rm[25][400555];

int fr[100555];

int d[400555],nd[400555];

int ind;

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

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