#include <iostream>
#include <vector>

#define NMAX 100005

using namespace std;

int n, m, etl,
    t[NMAX], niv[NMAX], firstOcc[NMAX],
    sparse[8 * 100000 + 5][20], lg2[2 * NMAX];
bool v[NMAX];
vector<int> eulerTour, fii[NMAX];

inline void constructEulerTour(int nod = 1) {
    v[nod] = 1;
    firstOcc[nod] = eulerTour.size();
    eulerTour.push_back(nod);
    for(const auto &el : fii[nod])
        if(!v[el]) {
            constructEulerTour(el);
            eulerTour.push_back(nod);
        }
}

inline void constructLCA() {
    for(int i = 1; i <= etl; ++i)
        sparse[i][0] = eulerTour[i];
    for(int sz = 1; (1 << sz) <= etl; ++sz) {
        for(int i = 1; i + (1 << sz) - 1 <= etl; ++i) {
            const int v1 = sparse[i][sz - 1],
                      v2 = sparse[i + (1 << (sz - 1))][sz - 1];
            if(niv[v1] < niv[v2]) sparse[i][sz] = v1;
            else sparse[i][sz] = v2;
        }
    }
}

void precalcLg2() {
    lg2[1] = 0;
    for(int i = 2; i < 2 * NMAX; ++i)
        lg2[i] = lg2[i / 2] + 1;
}

int lca(int x, int y) {
    x = firstOcc[x];
    y = firstOcc[y];
    if(x > y) swap(x, y);
    int lg2dist = lg2[y - x + 1];
    const int v1 = sparse[x][lg2dist],
              v2 = sparse[y - (1 << lg2dist) + 1][lg2dist];
    if(niv[v1] < niv[v2]) return v1;
    return v2;
}

int main()
{
    precalcLg2();
    freopen("lca.in", "r", stdin);
    freopen("lca.out", "w", stdout);
    scanf("%d%d", &n, &m);
    niv[1] = 1, niv[0] = 2e9;
    for(int i = 2, x; i <= n; ++i) {
        scanf("%d", &x);
        t[i] = x;
        niv[i] = niv[x] + 1;
        fii[x].push_back(i);
    }
    eulerTour.push_back(0);
    constructEulerTour();
    etl = eulerTour.size() - 1;
    constructLCA();
    for(int i = 1, x, y; i <= m; ++i) {
        scanf("%d%d", &x, &y);
        printf("%d\n", lca(x, y));
    }
    return 0;
}