#include <fstream>
#include <vector>
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
#define LG 20
#define NMAX 100005
int rmq[LG][NMAX<<2];
int Level[NMAX<<1], Euler[NMAX<<1], Lg[NMAX<<1], First[NMAX<<1];
int N,M,K;
vector <int> G[NMAX];
void dfs(int,int);
void Rmq();
int lca(int,int);
void read();
void solve();
int main()
{
    read();
    solve();
    return 0;
}
void read()
{
    f>>N>>M;
    for(int i=2;i<=N;++i)
    {
        int x;
        f>>x;
        G[x].push_back(i);
    }
}
void solve()
{
    dfs(1,0);
    Rmq();
    for(int i=1;i<=M;++i)
    {   int x,y;
        f>>x>>y;
        g<<lca(x,y)<<'\n';
    }
}
void dfs(int nod, int lvl)
{
    Euler[++K]=nod;
    Level[K]=lvl;
    First[nod]=K;
    for(vector <int>::iterator it=G[nod].begin();it!=G[nod].end();++it)
    {
        dfs(*it,lvl+1);
        Euler[++K]=nod;
        Level[K]=lvl;
    }
}
void Rmq()
{
    for(int i=2;i<=K;++i)
        Lg[i]=Lg[i>>1]+1;
    for(int i=1;i<=K;++i)
        rmq[0][i]=i;
    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(Level[rmq[i-1][j+l]]<Level[rmq[i][j]])
            rmq[i][j]=rmq[i-1][j+l];

    }
}
int lca(int x,int y)
{
    int diff,sh,a,b,l,sol;
    a=First[x];b=First[y];
    if(a>b) swap(a,b);
    diff=b-a+1;
    l=Lg[diff];
    sol=rmq[l][a];
    sh=diff-(1<<l);
    if(Level[sol]>Level[rmq[l][a+sh]])
        sol=rmq[l][a+sh];
    return Euler[sol];
}