#include <fstream>
#include <vector>
#define pb push_back
#define NMAX 100005
#define LMAX 20

using namespace std;

typedef vector<int>::iterator iter;
FILE* f=freopen("lca.in","r",stdin);
FILE* o=freopen("lca.out","w",stdout);

int n,m;
vector<int> G[NMAX];
int eul[NMAX<<1],lvl[NMAX<<1],first[NMAX],Log[NMAX<<1];
int rmq[LMAX][NMAX<<1];
int k;

void EulerWalk(int x, int lev)
{
    eul[++k]=x;
    first[x]=k;
    lvl[k]=lev;
    for(iter i=G[x].begin();i<G[x].end();++i)
    {
            EulerWalk(*i,lev+1);
            eul[++k]=x;
            lvl[k]=lev;
    }
}

void RMQ()
{
    rmq[0][1]=1;
    for(int i=2;i<=k;++i)
    {
        Log[i]=Log[i>>1]+1;
        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(lvl[rmq[i-1][j+l]]<lvl[rmq[i][j]])
                rmq[i][j]=rmq[i-1][j+l];
        }
    }
}

int LCA(int a, int b)
{
    a=first[a];
    b=first[b];
    if(a>b) swap(a,b);
    int dist=b-a+1;
    int lg=Log[dist];
    int offs=dist-(1<<lg);
    int sol=rmq[lg][a];
    if(lvl[rmq[lg][a]]>lvl[rmq[lg][a+offs]])
    {
        sol=rmq[lg][a+offs];
    }
    return eul[sol];
}

int main()
{
    scanf("%d%d",&n,&m);

    for(int i=2;i<=n;++i)
    {
        int x;
        scanf("%d",&x);
        G[x].pb(i);
    }

    EulerWalk(1,0);
    RMQ();

    for(int i=1;i<=m;++i)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        printf("%d\n",LCA(x,y));
    }

    return 0;
}