#include <bits/stdc++.h>
using namespace std;
ifstream f("lca.in");
ofstream g("lca.out");
const int NMAX = 100005;
int n , m, dp[23][NMAX], Niv[NMAX], Nvmax;
vector <int> Graf[NMAX];
inline void Read() {
    int x;
    f >> n >> m;
    for(int i = 2; i <= n ; i++) {
        f>> x;
        dp[0][i] = x;
        Graf[x].push_back(i);
    }
    for(int k = 1; (1<<k)<= n ; k++) {
        for(int i = 1; i <= n ; i++) {
            dp[k][i] = dp[k-1][dp[k-1][i]];
        }
    }
}
inline void Dfs(int nod, int nivel) {

    Niv[nod] = nivel;
    Nvmax = nivel;
    for(auto i: Graf[nod]) {
        Dfs(i, nivel+1);
    }
}
inline int Stramos(int x, int y) { ///returneaza al y-lea stramos al lui x

    int p = x;
    for(int i = 0; i <= 20; i++)
    {
        if( y & (1<<i) ){
            p = dp[i][p];
        }
    }
    return p;
}
inline int Cb(int x, int y) {

    int st = 0, dr = Nvmax, ret = -1;
    while(st <=  dr) {
        int m = (st + dr) /2;
        if(Stramos(x,Niv[x] - m) == Stramos(y,Niv[x] - m)) {
            st = m + 1;
            ret = Stramos(x,Niv[x] - m);
        }
        else
            dr = m - 1;
    }
    return ret;

}
inline void Solve(int x, int y) {

    if(Niv[x] < Niv[y])
        swap(x,y);
    x = Stramos(x, Niv[x] - Niv[y]);
    if(x != y)
        g<< Cb(x,y) << "\n";
    else
        g<< x << "\n";

}
int main()
{
    int x, y;
    Read();
    Dfs(1,0);
    Nvmax++;
    //g<< Stramos (5,1);
    for(int i = 1 ; i <= m; i++) {
        f>> x >> y;
        //g<< x << y << "\n";
        Solve(x,y);
    }
    return 0;
}