#include <fstream>
#include <vector>

#define NMAX 100005
#define LGMAX 20

using namespace std;

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

int n, m;
int up[NMAX][LGMAX];
int level[NMAX];
vector<int> edges[NMAX]; 

void dfs(int node, int parent, int lvl) {
    level[node] = lvl;
    up[node][0] = parent;
    for (auto child : edges[node]) {
        for (int i = 1; i < LGMAX; i++) {
            up[child][i] = up[up[child][i - 1]][i];
        }
        dfs(child, node, lvl + 1);
    }
}

int main() {
    f >> n >> m;

    for (int i = 2; i <= n ; i++) {
        int x;
        f >> x;
        edges[x].push_back(i);
    }

    dfs(1, 1, 0);

    for (int i = 0; i < m; i++) {
        int x, y;
        f >> x >> y;

        if (level[x] < level[y]) {
            swap(x, y);
        }

        int diff = level[x] - level[y];
        for (int i = LGMAX - 1; i >= 0; i--) {
            if (diff & (1 << i)) {
                x = up[x][i];
            }
        }

        if (x == y) {
            g << x << "\n";
            continue;
        }

        for (int i = LGMAX - 1; i >= 0; i--) {
            if (up[x][i] != up[y][i]) {
                x = up[x][i];
                y = up[y][i];
            }
        }

        g << up[x][0] << "\n";
    }

    return 0;
}