#include <fstream>
#include <vector>
#include <cmath>
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
int rmq[20][200005], e[400005], poz[200005], ban[200005], nr;
vector <int> v[200005];
void dfs(int nod)
{   int i;
    e[++nr]=nod;
    poz[nod]=nr;
    for(i=0; i<v[nod].size(); i++)
        if(ban[v[nod][i]]==0)
        {
            ban[v[nod][i]]=ban[nod]+1;
            dfs(v[nod][i]);
            e[++nr]=nod;
        }
 }

int main()
{
    int n, m, t, i, j, aux, x, y, p;
    f >> n >> m;
    for(i=2; i<=n; i++)
    {
        f >> t;
        v[t].push_back(i);
    }
    ban[1]=0;
    dfs(1);
    for(i=1; i<=nr; i++) rmq[0][i]=e[i];
    for(j=1;(1<<j)<=nr;j++)
      for(i=1;i+(1<<j)-1<=nr;i++)
        if(ban[rmq[j-1][i]]<ban[rmq[j-1][i+(1<<(j-1))]]) rmq[j][i]=rmq[j-1][i];
        else rmq[j][i]=rmq[j-1][i+(1<<(j-1))];

    for(i=1; i<=m; i++)
    {
        f >> x >> y;
        x=poz[x];  y=poz[y];
        if(x>y) swap(x,y);
        p=log2(y-x+1);
        g<<min(rmq[p][x],rmq[p][y-(1<<p)+1])<<'\n';
    }
    return 0;
}