#include<cstdio>
#include<vector>
#define MAX_N 100000
#define oo 0x3f3f3f3f
using namespace std;

int segTree[8*MAX_N+2], 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 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++;
    }
}

void buildSegmentTree(int low, int high, int pos) {
    if(low == high) {
        segTree[pos] = low;
        return;
    }
    int mid = (low + high) >> 1;
    buildSegmentTree(low,mid,2*pos+1);
    buildSegmentTree(mid+1,high,2*pos+2);
    if(niv[segTree[2*pos+1]] < niv[segTree[2*pos+2]])
        segTree[pos] = segTree[2*pos+1];
    else segTree[pos] = segTree[2*pos+2];
}

int rangeMinQuery(int low, int high, int pos) {
    if(a <= low && high <= b)
        return segTree[pos];
    if(a > high || b < low)
        return 2*MAX_N+2;
    int mid = (low + high) >> 1;
    int r1 = rangeMinQuery(low,mid,2*pos+1);
    int r2 = rangeMinQuery(mid+1,high,2*pos+2);
    if(niv[r1] < niv[r2])
        return r1;
    else return r2;

}

inline int LCA(int x, int y) {
    a = ap[x];
    b = ap[y];
    if(a > b)
        Swap(a,b);
    int sol = rangeMinQuery(0,k-1,0);
    return E[sol];
}

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);
    niv[2*MAX_N+2] = oo;
    buildSegmentTree(0,k-1,0);
    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;
}