#include<cstdio>
#include<vector>
#include<cmath>
#define max_n 100002
using namespace std;
vector<int> graf[max_n];
int i, n, m, lg, h[max_n], primul[max_n], a[20][max_n*4], x, y, nr;
void dfs(int poz, int d){
    vector<int>::iterator it;
    h[poz]=d; a[0][++lg]=poz; if (primul[poz]==0) primul[poz]=lg;
    for (it=graf[poz].begin();it!=graf[poz].end();it++) {
        dfs(*it, d+1);
        a[0][++lg]=poz;
    }
}
void citire(){
    ///locale: graf
    scanf("%d%d", &n, &m); lg=0;
    for (i=2;i<=n;i++) {scanf("%d", &x); graf[x].push_back(i);}
    dfs(1,1);
}
void create_rmq(){
    int i, j;
    ///a[i][j]=minim pe intervalul [j, j+2^i-1] -> 2^i elemente incepand din j
    for (i=1;(1<<i)<=lg;i++)
        for (j=1;j+(1<<i)-1<=lg;j++) {
            if ((i==1)&&(j==17))
                x=x;
            if (h[a[i-1][j]]<=h[a[i-1][j+(1<<(i-1))]] ) a[i][j]=a[i-1][j];
                 else a[i][j]=a[i-1][j+(1<<(i-1))];
        }
}
int main(){
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    citire();
    create_rmq();
    for (i=1;i<=m;i++) {
        scanf("%d%d", &x, &y);
        x=primul[x]; y=primul[y]; if (x>y) swap(x,y);
        if (x==y) {printf("%d\n", h[x]); continue;}
        nr=log2(y-x);
        ///a[i][j]=minim pe intervalul [j, j+2^i-1] -> 2^i elemente incepand din j
        if (h[a[nr][x]]<=h[a[nr][y+1-(1<<nr)]]) printf("%d\n", a[nr][x]);
            else printf("%d\n", a[nr][y+1-(1<<nr)]);
    }
    return 0;
}