#include<algorithm>
#include <vector>

using namespace std;

#define foreach(V) for(typeof (V).begin() it = (V).begin(); it != (V).end(); ++it)

#define Nmax 100005
#define Nlog 20

int n;
int E[ Nmax<<1],nt,L[ Nmax<<1],F[Nmax];
int Rmq[Nmax << 2][Nlog],lg[Nmax << 1];

vector <int> G[Nmax];

inline int lca(int a,int b)
{
    int misc,k,sol;
    a=F[a];
    b=F[b];
    if (a>b) 
        swap(a,b);
        
    k=lg[b-a+1];
    misc=b-a+1-(1<<k);
    sol=Rmq[a][k];
    if (L[sol] > L[ Rmq[a+misc][k] ])
        sol=Rmq[a+misc][k];
        
    return E[sol];
}

void df(int k,int niv)
{
    E[++nt]=k;
    L[nt]=niv;
    F[k]=nt;
    
    foreach(G[k])
        {
		df(*it, niv+1);
        
        E[++nt]=k;
        L[nt]=niv;
        }
}

int main()
{
    int a,b,m;
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    scanf("%d%d",&n,&m);
    for(int i=2;i<=n;++i)
        {
        scanf("%d",&a);		
        G[a].push_back(i);
        }
    
    df(1,0);
    
    Rmq[1][0]=1;
    for(int i=2;i<=nt;++i)
        {
        lg[i]=lg[i>>1]+1;
        Rmq[i][0]=i;
        }
        
    for(int i=1; (1<<i)<nt ; ++i)
        for(int j=1 , p=(1<<(i-1)); j <= nt - (1 << i) ;++j)
            {
            Rmq[j][i]=Rmq[j][i-1];
            if (L[ Rmq[j][i] ] > L[ Rmq[j+p][i-1] ])
                Rmq[j][i]= Rmq[j+p][i-1];
            }
    
    for(; m ;--m)
        {
        scanf("%d%d",&a,&b);
        printf("%d\n",lca(a,b));
        }
    
    return 0;
}