#include <fstream>
#include <vector>

using namespace std;
ifstream cin("lca.in");
ofstream cout("lca.out");
const int NMAX = 1e5 + 7;
const int LMAX = 18;
vector<int> g[NMAX];

int root = 1;

vector<int> euler;
int inveuler[NMAX];
int depth[NMAX];
int rmq[LMAX][(1 << LMAX)];
void liniarizare(int node, int parent, int dep)
{
    depth[node] = dep;
    euler.push_back(node);
    for(auto i : g[node]){
        if(i == parent)
            continue;
        liniarizare(i, node, dep + 1);
        euler.push_back(node);
    }
}
void rmq_init()
{
    int i, j;
    for(i = 0; i < euler.size(); i++){
        rmq[0][i] = i;
        inveuler[euler[i]] = i;
    }
    for(i = 1; i < LMAX; i++)
        for(j = 0; j + (1 << (i - 1)) < euler.size(); j++){
            if(depth[euler[rmq[i - 1][j]]] < depth[euler[rmq[i - 1][j + (1 << (i - 1))]]])
                rmq[i][j] = rmq[i - 1][j];
            else
                rmq[i][j] = rmq[i - 1][j + (1 << (i - 1))];
        }
}
int logaritm(int x)
{
    return (31 - __builtin_clz(x));
}
int query_rmq(int a, int b)
{
    a = inveuler[a];
    b = inveuler[b];
    if(a > b)
        swap(a, b);
    int lenght = logaritm(b - a + 1);
    if(rmq[lenght][a] <= rmq[lenght][b - (1 << lenght) + 1])
        return rmq[lenght][a];
    return rmq[lenght][b - (1 << lenght) + 1];
}
int main() {
    int n, m, q;
    cin >> n >> q;
    for(int i = 2; i <= n; i++) {
        int x, y; cin >> x;
        g[x].push_back(i);
    }
    liniarizare(1, -1, 1);
    rmq_init();
    for(int i = 0; i < q; i++) {
        int x, y; cin >> x >> y;
        cout << euler[query_rmq(x, y)] << endl;
    }
    return 0;
}