#include <iostream>
#include <vector>

#define NMAX 100005

using namespace std;

int n, m, etl,
    t[NMAX], niv[NMAX], firstOcc[NMAX],
    segt[4 * 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(int st = 1, int dr = etl,
                         int ind = 1) {
    if(st == dr) {
        segt[ind] = eulerTour[st];
        return;
    }

    int mij = (st + dr) / 2;
    constructLCA(st, mij, 2 * ind);
    constructLCA(mij + 1, dr, 2 * ind + 1);
    if(niv[segt[2 * ind]] < niv[segt[2 * ind + 1]])
        segt[ind] = segt[2 * ind];
    else segt[ind] = segt[2 * ind + 1];
}

inline int queryLCA(int st, int dr,
                    int sst = 1, int sdr = etl,
                    int ind = 1) {
    if(st > dr) return 0;
    if(st == sst && dr == sdr) return segt[ind];

    int smij = (sst + sdr) / 2;
    const int v1 = queryLCA(st, min(dr, smij), sst, smij, 2 * ind),
              v2 = queryLCA(max(st, smij + 1), dr, smij + 1, sdr, 2 * ind + 1);
    if(niv[v1] < niv[v2]) return v1;
    return v2;
}

int lca(int x, int y) {
    x = firstOcc[x];
    y = firstOcc[y];
    return queryLCA(min(x, y), max(x, y));
}

int main()
{
    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;
}