#include <fstream>
#include <vector>
using namespace std;

ifstream fin("lca.in");
ofstream fout("lca.out");

vector<int> a[100003];
int n, m;
int rmq[210000][20], log[210000];
vector<int> e, l, p;

void dfs(int x=1, int y=0, int lv=1)
{
    e.push_back(x);
    l.push_back(lv);
    for(int i=0;i<a[x].size();++i)
        dfs(a[x][i], x, lv+1);
    e.push_back(y);
    l.push_back(lv-1);
}

int main()
{
    fin>>n>>m;
    for(int i=1;i<n;++i)
    {
        int x;
        fin>>x;
        a[x].push_back(i+1);
    }
    dfs();
    e.pop_back();
    int L=e.size();
    for(int i=0;i<=n+3;++i) p.push_back(0);
    for(int i=0;i<L;++i)
        if(p[e[i]]==0) p[e[i]]=i;
    for(int i=2;i<=L;++i) log[i]=log[i/2]+1;
    for(int i=0;i<L;++i)
    {
        rmq[i][0]=i;
    }
    for(int j=1;j<=log[L];++j)
        for(int i=0;i+(1<<j)-1<L;++i)
        {
            if(l[rmq[i][j-1]]<l[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];
        }
    for(int i=1;i<=m;++i)
    {
        int x, y, u, v, k;
        fin>>u>>v;
        x=p[u];
        y=p[v];
        if(x>y) swap(x, y);
        k=log[y-x+1];
        if(l[rmq[x][k]]<l[rmq[y-(1<<k)+1][k]]) fout<<e[rmq[x][k]]<<"\n";
        else fout<<e[rmq[y-(1<<k)+1][k]]<<"\n";
    }
    return 0;
}