#include<cstdio>
#include<vector>
using namespace std;
const int nmax = 100005;
const int lmax = 18;
int n,q,i,j,p,x,y,cnt,dif,lca,lev[nmax],first[nmax],euler[2*nmax],rmq[lmax][nmax];
vector<int> v[nmax];
void dfs(int x)
{
    euler[++cnt]=x;
    first[x]=cnt;
    for(vector<int>::iterator it=v[x].begin();it!=v[x].end();it++)
    {
        lev[*it]=lev[x]+1;
        dfs(*it);
        euler[++cnt]=x;
    }
}
int main()
{
	freopen("lca.in","r",stdin);
	freopen("lca.out","w",stdout);
	scanf("%d%d",&n,&q);
	for(i=2;i<=n;i++)
	{
	    scanf("%d",&x);
	    v[x].push_back(i);
	}
	lev[1]=1; dfs(1);
	for(i=1;i<=cnt;i++) rmq[0][i]=euler[i];
	for(i=1,p=2;p<=cnt;i++,p<<=1)
        for(j=1;j<=cnt-p+1;j++)
        {
            rmq[i][j]=rmq[i-1][j];
            if(lev[rmq[i-1][j+p/2]]<lev[rmq[i][j]])
                rmq[i][j]=rmq[i-1][j+p/2];
        }
    for(;q;q--)
    {
        scanf("%d%d",&x,&y);
        if(x==y) {printf("%d\n",x); continue;}
        x=first[x]; y=first[y];
        if(x>y) swap(x,y);
        dif=y-x+1;
        for(i=0,p=1;p<=dif;i++,p<<=1); i--; p>>=1;
        lca=rmq[i][x];
        if(lev[rmq[i][y-p+1]]<lev[lca])
            lca=rmq[i][y-p+1];
        printf("%d\n",lca);
    }
	return 0;
}