#include <fstream>
#include <vector>
#include <cmath>
using namespace std;

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

int d[200005][20], euler[400005], poz[200005], h[200005], nr;
vector <int> v[200005];

void dfs(int nod)
{   int i;
    euler[++nr]=nod;
    poz[nod]=nr;
    for(i=0; i<v[nod].size(); i++)
        if(h[v[nod][i]]==0)
        {
            h[v[nod][i]]=h[nod]+1;
            dfs(v[nod][i]);
            euler[++nr]=nod;
        }
 }

int main()
{
    int n, m, t, i, j, aux, x, y, p;
    in >> n >> m;
    for(i=2; i<=n; i++)
    {
        in >> t;
        v[t].push_back(i);
    }

    h[1]=0;
    dfs(1);

    for(i=1; i<=nr; i++) d[i][0]=euler[i];

    for(j=1;(1<<j)<=nr;j++)
      for(i=1;i+(1<<j)-1<=nr;i++)
        if(h[d[i][j-1]]<h[d[i+(1<<(j-1))][j-1]]) d[i][j]=d[i][j-1];
        else d[i][j]=d[i+(1<<(j-1))][j-1];

    for(i=1; i<=m; i++)
    {
        in>>x>>y;

        x=poz[x];  y=poz[y];
        if(x>y) swap(x,y);
        p=log2(y-x+1);
        out<<min(d[x][p],d[y-(1<<p)+1][p])<<'\n';
    }

    return 0;
}