#include <fstream>
#include <vector>
#define nmax 100002
#define lgmax 20
using namespace std;
ifstream fin("lca.in");
ofstream fout("lca.out");

int h[nmax*2],l[nmax*2],f[nmax],lg[nmax*2],rmq[lgmax][nmax*2],k=0;
vector <int> graf[nmax];


void dfs(int nod,int level)
{
    h[++k]=nod;
    l[k]=level;
    f[nod]=k;
    int lgg=graf[nod].size();
    for(int i=0;i<lgg;i++)
    {
        dfs(graf[nod][i],level+1);
        h[++k]=nod;
        l[k]=level;
    }
}

void rmq_cre()
{
    for(int i=2;i<=k;i++)
        lg[i]=lg[i/2]+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++)
        {
            rmq[i][j]=rmq[i-1][j];
            if(l[rmq[i][j]]>l[rmq[i-1][j+(1<<i-1)]])
                rmq[i][j]=rmq[i-1][j+(1<<i-1)];
        }
    }
}

void lca(int a,int b)
{
    a=f[a];
    b=f[b];
    if(a>b)
    {
        int aux=a;
        a=b;
        b=aux;
    }
    int dif=b-a+1;
    int log=lg[dif];
    int sh=dif-(1<<log);
    int sol=rmq[log][a];
    if(l[sol]>l[rmq[log][a+sh]])
        sol=rmq[log][a+sh];
    fout<<h[sol]<<"\n";
}

int main()
{
    int n,m,x,y;
    fin>>n>>m;
    for(int i=2;i<=n;i++)
    {
        fin>>x;
        graf[x].push_back(i);
    }
    dfs(1,0);
    rmq_cre();
    for(int i=1;i<=m;i++)
    {
        fin>>x>>y;
        lca(x,y);
    }
    return 0;
}