#include <fstream>
#include <vector>
#include <stack>

using namespace std;

ifstream f("lca.in");
ofstream g("lca.out");

int n,q,euler[200006],cnt,niv[200006],ap[200001],rmq[200006][20],lg[200006];

vector<int>v[100001];

void oil(int x,int r)
{
    cnt++;
    euler[cnt]=x;
    niv[cnt]=r;
    ap[x]=cnt;

    for(int i=0;i<v[x].size();++i)
    {
        oil(v[x][i],r+1);

        cnt++;
        euler[cnt]=x;
        niv[cnt]=r;

    }

}

int main()
{
    f>>n>>q;

    for(int i=2;i<=n;++i)
    {
        int x;
        f>>x;
        v[x].push_back(i);
    }
    oil(1,0);

    rmq[1][0]=euler[1];
    for(int i=2;i<=cnt;++i)
        {
            rmq[i][0]=euler[i];
            lg[i]=lg[i/2]+1;
        }

    for(int i=1; (1<<i)<=cnt;i++)
    {

        for(int j=1;j <= cnt -(1<<i)+1;j++)
        {
            if(niv[ap[rmq[j][i-1]]]<niv[ap[rmq[j+(1<<(i-1))][i-1]]])
                rmq[j][i] = rmq[j][i-1];
            else
                rmq[j][i] = rmq[j+(1<<(i-1))][i-1];
        }

    }

    for(int i=1;i<=q;++i)
    {

        int a,b,x;
        f>>a>>b;
        a=ap[a];
        b=ap[b];
        if(a>b)
            swap(a,b);
        x = lg[b-a+1];
        g<<min(rmq[a][x],rmq[b-(1<<x)+1][x])<<'\n';

    }

    return 0;
}