#include<cstdio>
#include<vector>
using namespace std;
vector<int>L[100100];
int n,m,i,j,v[200100],x[20][200100],a,b,t[200100],p[200100],y[200100],nr,d,q;
FILE *f,*g;
void dfs(int nod,int niv){
    int i;
    x[0][++nr]=nod;
    y[nod]=niv;
    if(v[nod]==0)
        v[nod]=nr;
    for(i=0;i<L[nod].size();i++){
        dfs(L[nod][i],niv+1);
        x[0][++nr]=nod;
    }
}
int minim(int a,int b){
    if(a<b)
        return a;
    return b;
}
void chg(int a,int b){
    int aux;
    aux=a;
    a=b;
    b=aux;
    return;
}
int main(){
    f=fopen("lca.in","r");
    g=fopen("lca.out","w");
    fscanf(f,"%d%d",&n,&m);
    p[1]=0;
    for(i=1;i<=200000;i++){
        p[i]=p[i/2]+1;
    }
    for(i=2;i<=n;i++){
        fscanf(f,"%d",&t[i]);
        L[t[i]].push_back(i);
    }
    dfs(1,1);
    for(i=1;i<=p[n];i++){
        a=1<<(i-1);
        for(j=1;j<=nr;j++){
            if(a+j<=nr){
                if(y[x[i-1][j]]<y[x[i-1][j+a]])
                    x[i][j]=x[i-1][j];
                else
                    x[i][j]=x[i-1][j+a];
            }
            else
                x[i][j]=x[i-1][j];
        }
    }
    for(i=1;i<=m;i++){
        fscanf(f,"%d%d",&a,&b);
        a=v[a];
        b=v[b];
        if(a>b)
            chg(a,b);
        q=b-a+1;
        d=1<<(p[q]);
        if(y[x[p[q]][a]]<y[x[p[q]][b-d+1]])
            fprintf(g,"%d\n",x[p[q]][a]);
        else
            fprintf(g,"%d\n",x[p[q]][b-d+1]);
        /*if(y[x[p[q]-1][a]]>y[x[p[q]-1][b-d+1]])
            fprintf(g,"%d\n",x[p[q]-1][b-d+1]);
        else
            fprintf(g,"%d\n",x[p[q]-1][a]);
        */
    }



    fclose(f);
    fclose(g);
    return 0;
}