#include <bits/stdc++.h>
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int rmq[400004][15],lv[400004],ap[400004],p,pe[400004],k,j,n,m,x,y,mn;
vector <int> v[100005];

void euler(int nod_c, int niv)
{
    lv[++k]=niv;
    pe[k]=nod_c;
    if(ap[nod_c]==0)
        ap[nod_c]=k;
    for(int i=0;i<v[nod_c].size();i++)
    {
        euler(v[nod_c][i],niv+1);
        pe[++k]=nod_c;
        lv[k]=niv;
    }
}
int main()
{
    int i;
   f>>n>>m;
    for(i=2; i<=n; i++)
    {
        f>>x;
        v[x].push_back(i);
    }
    euler(1,0);
    for(i=1; i<=k; i++)
        rmq[i][0]=i;
    for(j=1; (1<<j)<=k; j++)
        for(i=1; i<=k; i++)
        {
            if(lv[rmq[i][j-1]]<lv[rmq[i+(1<<(j-1))][j-1]])
                rmq[i][j]=rmq[i][j-1];
            else rmq[i][j]=rmq[i+(1<<(j-1))][j-1];
        }
    for(i=1; i<=m; i++)
    {
        f>>x>>y;
        x=ap[x];
        y=ap[y];
        if(x>y) swap(x,y);
        p=log2(y-x+1);
        if(lv[rmq[x][p]]<lv[rmq[y-(1<<p)+1][p]])
            mn=rmq[x][p];
        else mn=rmq[y-(1<<p)+1][p];
        g<<pe[mn]<<'\n';
    }
    return 0;
}