#include <cstdio>
#define N 100002
#include <vector>

using namespace std;
FILE *f,*g;

int log[2*N],rmq[20][2*N],nivel[N],where[N],nr;
vector <int> fiu[N];

void RMQ()
{
    int poz=1;
    for(int i=1;i<=log[nr];++i)
    {
        for(int j=1;j+poz<=nr;++j)
        {
            if(nivel[rmq[i-1][j]]<nivel[rmq[i-1][j+poz]])
                rmq[i][j]=rmq[i-1][j];
            else
                rmq[i][j]=rmq[i-1][j+poz];
        }
        poz*=2;
    }
}
void dfs(int nod)
{
    rmq[0][++nr]=nod;
    where[nod]=nr;
    for(int i=0;i<fiu[nod].size();++i)
    {
        nivel[fiu[nod][i]]=nivel[nod]+1;
        dfs(fiu[nod][i]);
        rmq[0][++nr]=nod;
    }
}
int main()
{
    f=fopen("lca.in","r");
    g=fopen("lca.out","w");
    int n,m;
    fscanf(f,"%d %d",&n,&m);
    int x;
    for(int i=2;i<=n;++i)
    {
        fscanf(f,"%d",&x);
        fiu[x].push_back(i);
    }
    dfs(1);
    for(int i=2;i<=nr;++i)
        log[i]=log[i/2]+1;
    RMQ();
    int a,b,poz,dif,lin,val;
    for(int i=1;i<=m;++i)
    {
        fscanf(f,"%d %d",&a,&b);
        a=where[a];
        b=where[b];
        if(a>b) swap(a,b);
        dif=b-a+1;
        lin=log[dif];
        poz=(1<<lin);
        if(nivel[rmq[lin][a]]<=nivel[rmq[lin][b-poz+1]])
            val=rmq[lin][a];
        else
            val=rmq[lin][b-poz+1];
        fprintf(g,"%d\n",val);
    }
    fclose(f);
    fclose(g);
    return 0;
}