#include<fstream>


using namespace std;

typedef int var;

ifstream fin("lca.in");
ofstream fout("lca.out");

var *PARENT, *RANK, *PARENT2;
var n;
bool C[100001];

inline var lca(var &a, var &b) {
    while(RANK[PARENT2[a]] >= RANK[b]) a = PARENT2[a];
    while(RANK[PARENT2[b]] >= RANK[a]) b = PARENT2[b];
    while(RANK[a] > RANK[b]) a = PARENT[a];
    while(RANK[b] > RANK[a]) b = PARENT[b];
    while(PARENT2[a] != PARENT2[b]) {a = PARENT2[a]; b = PARENT2[b];}
    while(a!=b) {a = PARENT[a]; b = PARENT[b];}
    return a;
}


int main() {

    var i, q;
    var a, b;

    fin>>n>>q;
    PARENT = new var[n+1];
    RANK = new var[n+1];
    PARENT2 = new var[n+1];
    PARENT[1] = PARENT2[1] = RANK[1] = 0;
    PARENT[0] = PARENT2[0] = RANK[0] = -1;

    for(i=2; i<=n; i++) {
        fin>>PARENT[i];
        RANK[i] = RANK[PARENT[i]] + 1;
        b = RANK[PARENT[i]];
        if(!(b & (b - 1))) {
            PARENT2[i] = PARENT[i];
        } else {
            PARENT2[i] = PARENT2[PARENT[i]];
        }
    }

    while(q--) {
        fin>>a>>b;
        fout<<lca(a, b)<<'\n';
    }

    return 0;
}