#include <fstream>
#include <cmath>
#include <vector>
using namespace std;
ifstream in ("lca.in");
ofstream out ("lca.out");
vector <int> v[100002];
long n,m,viz[200002],st[200002],a[200002],nr,b,d[200002][50];
void dfs(int nod)
{
    a[++nr]=nod;
    st[nod]=nr;
    for(auto i:v[nod])
    {
        if(!viz[i])
            viz[i]=viz[nod]+1,dfs(i),a[++nr]=nod;
    }

}
int main()
{
in>>n>>m;
for(int i=2;i<=n;i++)
{
    in>>b;
    v[b].push_back(i);
}
viz[1]=1;
dfs(1);
for(int i=1;i<=nr;i++)
{
    d[i][0]=a[i];
}
for(int j=1;(1<<j)<=nr;j++)
{
    for(int i=1;i+(1<<j)-1<=nr;i++)
    {
        if(viz[d[i][j-1]]<viz[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(int k=1;k<=m;k++)
{
    int x,y;
    in>>x>>y;
    x=st[x];
    y=st[y];
    if(x>y)swap(x,y);
    int p=log2(y-x+1);
    int cmin=min(d[x][p],d[y-(1<<p)+1][p]);
    out<<cmin<<'\n';
}
    return 0;
}