#include <fstream>
#include <vector>

using namespace std;

ifstream cin ("lca.in");
ofstream cout ("lca.out");

const int M = 17;
const int N = 1e5;
int lg[N + 1], dp[N + 1][M + 1], h[N + 1];

int n, m, x, y;

vector <int> g[N + 1];

void dfs (int node, int parent)
{
    h[node] = h[parent] + 1;
    for (auto it : g[node])
        if (it != parent)
            dfs (it, node);
}

int lca (int x, int y)
{
    if (h[x] < h[y])
        swap(x, y);
    for (int i = lg[h[x]]; i >= 0; --i)
        if (h[x] - (1 << i) >= h[y]) x = dp[x][i];
    if (x == y)return x;
    for (int i = lg[h[x]]; i >= 0; --i)
        if (dp[x][i] != dp[y][i])
        {
            x = dp[x][i];
            y = dp[y][i];
        }
    return dp[x][0];
}

int main()
{
    cin >> n >> m;
    for (int i = 1; i < n; ++i)
        g[(dp[i + 1][0] = (cin >> x, x))].push_back(i + 1);///ce dracu e asta
    for (int i = 2; i <= n; ++i)
        lg[i] = lg[i >> 1] + 1;
    for (int j = 1; j <= lg[n]; ++j)
        for (int i = 1; i <= n; ++i)
            dp[i][j] = dp[dp[i][j - 1]][j - 1];
    dfs (1, 0);
    for (int i = 1; i <= m; ++i)
    {
        cin >> x >> y;
        cout << lca (x, y) << '\n';
    }
    return 0;
}