#include<bits/stdc++.h>
#define N 100030
using namespace std;

int d[N][18],L[N],n,q;
vector<int>V[N];

void DFS(int x, int lvl) {
    L[x]=lvl;
    for (auto it:V[x]) {
        DFS(it, lvl+1);
    }
}

int main() {
    ifstream cin("lca.in");
    ofstream cout("lca.out");
    cin>>n>>q;
    for (int i=2; i<=n; ++i) {
        int x; cin>>x;
        d[i][0]=x;
        V[x].push_back(i);
    }
    DFS(1,1);
    for (int j=1; (1<<j)<n; ++j) {
        for (int i=1; i<=n; ++i) d[i][j]=d[d[i][j-1]][j-1];
    }
    while (q--) {
        int x,y; cin>>x>>y;
        if (L[x]<L[y]) swap(x,y);
        while (L[x]!=L[y]) {
            int p=0;
            while (L[d[x][p+1]] && L[d[x][p+1]]>L[y]) ++p;
            x=d[x][p];
        }
        while (x!=y) {
            int p=0;
            while (d[x][p+1]!=d[y][p+1]) ++p;
            x=d[x][p]; y=d[y][p];
        }
        cout<<x<<'\n';
    }
    return 0;
}