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

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

#define N 100005
#define MaxLog 20

int n, q, k;
int H[N<<1], L[N<<1], F[N];
int rmq[MaxLog][N<<2], lg[N<<1];
vector<int>G[N];

void dfs(int nod, int level)
{
    H[++k]=nod;
    L[k]=level;
    F[nod]=k;
    for(auto it:G[nod])
    {
        dfs(it,level+1);
        H[++k]=nod;
        L[k]=level;
    }
}

void Rmq()
{
    for(int i=1; i<=k; i++)
        rmq[0][i]=i;

    for(int i=2; i<=k; i++)
        lg[i]=lg[i>>1]+1;

    for(int i=1; (1<<i)<k; i++)
    {
        for(int j=1; j<=k-(1<<i); j++)
        {
            int l= 1<<(i-1);
            rmq[i][j]=rmq[i-1][j];
            if(L[rmq[i-1][j+l]]<L[rmq[i][j]])
            {
                rmq[i][j]=rmq[i-1][j+l];
            }
        }
    }
}
int lca(int x, int y)
{
    int a,b,dif,nivel,extra,sol;
    a=F[x];
    b=F[y];

    if(a>b) swap(a,b);

    dif=b-a+1;
    nivel=lg[dif];
    extra=dif-(1<<nivel);
    sol=rmq[nivel][a];
    if(L[sol]>L[rmq[nivel][a+extra]])
    {
        return H[rmq[nivel][a+extra]];
    }
    return H[sol];
}
int main()
{
    int nod;
    fin>>n>>q;
    for(int i=2; i<=n; i++)
    {
        fin>>nod;
        G[nod].push_back(i);
    }
    dfs(1,0);
    Rmq();
    while(q--)
    {
        int x,y;
        fin>>x>>y;
        fout<<lca(x,y)<<'\n';
    }
    return 0;
}