#include <fstream>
#include <vector>
#define nmax (int)(1e5+1)
using namespace std;
ifstream cin("lca.in");
ofstream cout("lca.out");
int n,q,x,y,rmq[20][nmax],k,a[20][nmax],p[nmax],first[nmax];
vector<int>v[nmax];
void dfs(int nod,int l){
    rmq[0][++k]=l;
    a[0][k]=nod;
    first[nod]=k;
    for(auto i:v[nod]){
        dfs(i,l+1);
        rmq[0][++k]=l;
        a[0][k]=nod;
    }
}
signed main()
{
    cin>>n>>q;
    for(int i=2;i<=n;i++){
        cin>>x;
        v[x].push_back(i);
    }
    dfs(1,1);
    for(int i=1;(1<<i)<=k;i++)
        for(int j=1;j<=k;j++){
            rmq[i][j]=rmq[i-1][j];
            a[i][j]=a[i-1][j];
            if(j+(1<<(i-1))<=k&&rmq[i][j]>rmq[i-1][j+(1<<(i-1))]){
                rmq[i][j]=rmq[i-1][j+(1<<(i-1))];
                a[i][j]=a[i-1][j+(1<<(i-1))];
            }
        }
    for(int i=2;i<=n;i++)
        p[i]=p[i/2]+1;
    while(q--){
        cin>>x>>y;
        int st=min(first[x],first[y]),dr=max(first[x],first[y]),e=p[dr-st+1],lca=a[e][st];
        if(rmq[e][st]>rmq[e][dr-(1<<e)+1])
            lca=a[e][dr-(1<<e)+1];
        cout<<lca<<'\n';
    }
    return 0;
}