#include<cstdio>
#include<vector>
#include<algorithm>
#include<cctype>
#define MAX_N 100000
#define MAX_LOG 20
#define buf_SIZE 1 << 19
using namespace std;

int niv[2*MAX_N+1], E[2*MAX_N+1], ap[MAX_N+1], sparse[2*MAX_N+1][MAX_LOG];
int n, m, k, pos = buf_SIZE;
char buf[buf_SIZE];
vector<int> G[MAX_N+1];

inline char getChar(FILE *fin)
{
    if(pos == buf_SIZE)
    {
        fread(buf,1,buf_SIZE,fin);
        pos = 0;
    }
    return buf[pos++];
}

inline int read(FILE *fin)
{
    int res = 0;
    char ch;
    do
    {
        ch = getChar(fin);
    }while(!isdigit(ch));
    do
    {
        res = 10*res + ch - '0';
        ch = getChar(fin);
    }while(isdigit(ch));
    return res;
}

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

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

void RMQ()
{
    int i, j;
    for(i=0; i<k; i++)
        sparse[i][0] = i;
    for(j=1; (1 << j) <= k; j++)
        for(i=0; i + (1 << j) - 1 < k; 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 LCA(int x, int y)
{
    int low, high, z, l, result;
    low = ap[x];
    high = ap[y];
    if(low > high) swap(low,high);
    l = high - low + 1;
    z = log(l);
    if(niv[sparse[low][z]] < niv[sparse[low + l - (1 << z)][z]])
        result = sparse[low][z];
    else result = sparse[low + l - (1 << z)][z];
    return E[result];
}

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