#include <bits/stdc++.h>
#define MAXN 100000

int n;
std::vector <int> G[1 + MAXN];

int euler[1 + 2 * MAXN], last;
int f[1 + MAXN];
int depth[1 + 1 * MAXN];
void dfs(int node, int papa){
    depth[node] = 1 + depth[papa];
    f[node] = ++last;
    euler[last] = node;
    for(auto y: G[node]) if(y != papa){
        dfs(y, node);
        euler[++last] = node;
    }
}

int aint[8 * MAXN];

int left, right;
int rez;
void query(int p, int st, int dr){
    if(left <= st && dr <= right){
        if(depth[aint[p]] < depth[rez])
            rez = aint[p];
    }
    else{
        int m = (st + dr) / 2;
        if(left <= m) query(2 * p, st, m);
        if(right > m) query(2 * p + 1, m + 1, dr);
    }
}

void build(int p, int st, int dr){
    if(st == dr)
        aint[p] = euler[st];
    else{
        int m = (st + dr) / 2;
        build(2 * p, st, m);
        build(2 * p + 1, m + 1, dr);

        if(depth[aint[2 * p]] < depth[aint[2 * p + 1]])
            aint[p] = aint[2 * p];
        else
            aint[p] = aint[2 * p + 1];
    }
}

int lca(int u, int v){
    left = f[u], right = f[v], rez = 0;
    if(left > right) std::swap(left, right);
    query(1, 1, 2 * n);
    return rez;
}

int main(){
    FILE*fi,*fo;
    fi = fopen("lca.in","r");
    fo = fopen("lca.out","w");

    int m;
    fscanf(fi,"%d%d", &n, &m);
    for(int i = 2; i <= n; i++){
        int x;
        fscanf(fi,"%d", &x);
        G[i].push_back(x);
        G[x].push_back(i);
    }
    dfs(1, 0);
    build(1, 1, 2 * n);
    depth[0] = 1000000000;

    for(int i = 1; i <= m; i++){
        int x, y;
        fscanf(fi,"%d%d", &x, &y);
        fprintf(fo,"%d\n", lca(x, y));
    }

    return 0;
}