#include<fstream>
#include<vector>
#define NNMAX 200005
#define NMAX 100005
#define PMAX 20
using namespace std;
vector<int> G[NMAX];
int n, m;
int nn;
int d[PMAX][NNMAX];
int first[NMAX];
int p[NNMAX];
int x, y, _length, _p;
ifstream cin("lca.in");
ofstream cout("lca.out");
void dfs_euler(int nod, int tata)
{
    d[0][++nn] = nod;

    if(first[nod] == 0)
    {
        first[nod] = nn;
    }

    for(int i = 0; i < G[nod].size(); i++)
    {
        int fiu = G[nod][i];
        if(fiu != tata)
        {
            dfs_euler(fiu, nod);
            d[0][++nn] = nod;
        }
    }
}
void p_calc()
{
    for(int i = 1 + 1; i <= NNMAX; i++)
    {
        p[i] = 1 + p[i / 2];
    }
}
void rmq()
{
    for(int i = 1; (1 << i) <= nn; i++)
    {
        for(int j = 1; j <= nn; j++)
        {
            d[i][j] = min(d[i-1][j], d[i-1][j + (1<<(i-1))]);
        }
    }

    while(m--)
    {
        cin >> x >> y;
        x = first[x];
        y = first[y];
        if(x > y)
        {
            swap(x, y);
        }
        _length = y - x + 1;
        _p = p[_length];
        cout << min(
        d[_p][x],
        d[_p][y - (1 << _p) + 1]) << "\n";
    }
}
int main()
{
    cin >> n >> m;
    for(int i = 1 + 1; i <= n; i++)
    {
        cin >> x;
        G[x].push_back(i);
        G[i].push_back(x);
    }
    dfs_euler(1, 0);
    p_calc();
    rmq();
    return 0;
}