#include<cstdio>
#include<vector>
#define MAX_N 100000
#define MAX_LOG 18
using namespace std;

int sparse[2*MAX_N][MAX_LOG], E[2*MAX_N], niv[2*MAX_N+3], ap[MAX_N+1], n, m, a, b, k;
vector<int>G[MAX_N+1];

inline int log2(int x) {
    return 31 - __builtin_clz(x);
}

inline void Swap(int &x, int &y) {
    int aux = x;
    x = y;
    y = aux;
}

void DFS(int node, int level) {
    vector<int>::iterator it;
    E[k] = node;
    niv[k] = level;
    ap[node] = k;
    k++;
    for(it = G[node].begin(); it != G[node].end(); it++) {
        DFS(*it,level+1);
        E[k] = node;
        niv[k] = level;
        k++;
    }
}

inline int rangeMinQuery(int low, int high) {
    int l = high - low + 1;
    int k = log2(l);
    if(niv[sparse[low][k]] <= niv[sparse[low + l - (1 << k)][k]])
        return sparse[low][k];
    else return sparse[low + l - (1 << k)][k];
}

inline int LCA(int x, int y) {
    a = ap[x];
    b = ap[y];
    if(a > b)
        Swap(a,b);
    int sol = rangeMinQuery(a,b);
    return E[sol];
}

void RMQ(int n) {
    int i, j;
    for(i=0; i<n; i++)
        sparse[i][0] = i;
    for(j=1; (1 << j) <= n; j++)
        for(i=0; i + (1 << j) - 1 < n; i++)
            if(niv[sparse[i][j-1]] < niv[sparse[i + (1 << (j-1))][j-1]])
                sparse[i][j] = sparse[i][j-1];
            else sparse[i][j] = sparse[i + (1 << (j-1))][j-1];
}

int main() {
    int x, y;
    FILE *fin, *fout;
    fin = fopen("lca.in","r");
    fout = fopen("lca.out","w");
    fscanf(fin,"%d%d",&n,&m);
    for(int i=2; i<=n; i++) {
        fscanf(fin,"%d",&x);
        G[x].push_back(i);
    }
    DFS(1,0);
    RMQ(k);
    for(int i=1; i<=m; i++) {
        fscanf(fin,"%d%d",&x,&y);
        fprintf(fout,"%d\n",LCA(x,y));
    }
    fclose(fin);
    fclose(fout);
    return 0;
}