#include <cstdio>
#include <vector>

using namespace std;

vector<int> v[100010];
int logg[200010],l,rmq[200010][25],niv[100010],first[100010],vaz[100010];

void dfs(int nod,int nivel)
{
    vaz[nod]=1;
    rmq[++l][0]=nod;
    niv[nod]=nivel;
    first[nod]=l;
    for(int i=0;i<v[nod].size();i++)
        if(vaz[v[nod][i]]==0)
        {
            dfs(v[nod][i],nivel+1);
            rmq[++l][0]=nod;
        }
}

int main()
{
    freopen("lca.in","r",stdin);
    freopen("lca.out","w",stdout);
    int n,m,sol,l1,x,a,b;
    scanf("%d%d",&n,&m);
    for(int i=2;i<=n;i++)
    {
        scanf("%d",&x);
        v[x].push_back(i);
    }
    dfs(1,0);
    logg[1]=0;
    for(int i=2;i<=l;i++)
        logg[i]=logg[i/2]+1;
    for(int i=1;i<=logg[l];i++)
        for(int j=1;j+(1<<i)<=l;j++)
            if(niv[rmq[j][i-1]]<=niv[rmq[j+(1<<(i-1))][i-1]]) rmq[j][i]=rmq[j][i-1];
            else rmq[j][i]=rmq[j+(1<<(i-1))][i-1];
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&a,&b);
        if(first[a]<=first[b]) {a=first[a];b=first[b];}
        else {a=first[b];b=first[a];}
        l1=logg[b-a+1];
        sol=min(rmq[a][l1],rmq[b-(1<<l1)+1][l1]);
        printf("%d\n",sol);
    }
    return 0;
}