#include <fstream>
#include <vector>
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int n,m,k,b[100005<<1],lev[100005<<1],prim[100005],rmq[19][100005<<1],lg[100005<<1];
vector <int> a[1<<17];
void citire(){
    f>>n>>m;
    int x,i;
    for(i=2;i<=n;i++)
    {
        f>>x;
        a[x].push_back(i);
    }

}
void rec(int nod, int lv){
    b[++k]=nod;
    lev[k]=lv;
    prim[nod]=k;
    for(int i=0;i<(int)a[nod].size();i++)
    {
        rec(a[nod][i],lv+1);
        b[++k]=nod;
        lev[k]=lv;
    }
}
void calcrmq()
{
    int i,j;
    lg[1]=0;
    for(i=2;i<=k;i++)
        lg[i]=lg[i/2]+1;
    for(i=1;i<=k;i++)
        rmq[0][i]=b[i];
    for(i=1;(1<<i)<=k;i++)
        for(j=1;j<=k-(1<<(i-1));j++)
        rmq[i][j]= min( rmq[i-1][j] , rmq[i-1][j+(1<<(i-1))] );
}
int lca(int x, int y){
    int dif1,l,sol,dif2 ;
	int a1 = prim[x], b1 = prim[y];
	if(a1 > b1) swap(a1, b1);
	dif1 = b1 - a1 + 1;
	l = lg[dif1];
	sol = rmq[l][a1];
	dif2 = dif1 - (1 << l);
	if(lev[sol] > lev[rmq[l][b1-(1<<l)+1]])
		sol = rmq[l][b1-(1<<l)+1];
	return sol;
}
int main()
{
    int x,y,i;
    citire();
    rec(1,1);
    calcrmq();
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        g<<lca(x,y)<<"\n";
    }
    return 0;
}