#include <bits/stdc++.h>
using namespace std;
const int N=2e5+10;
struct Block{int st,ed;}B[N],B2[N];int len,len2;
int n,a[N],nxt[N];
int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++)scanf("%d",&a[i]);  a[n+1]=-1;
    for(int i=1;i<n;i++)if(a[i]==a[i+1])nxt[i]=i+1;else nxt[i]=0;
	len=0;
    for(int i=1,st=1;i<=n;i++)
    {
        if(a[i]!=a[i+1])
        {
            B[++len]={st,i};
            st=i+1;
        }
    }
    while(len)
    {
        len2=0;
        for(int i=1;i<=len;i++)
        {
            printf("%d ",B[i].st);
            B[i].st=nxt[B[i].st];
            if(B[i].st)
            {
                if(len2 && a[B2[len2].ed]==a[B[i].st])
				{
					nxt[B2[len2].ed]=B[i].st;
					B2[len2].ed=B[i].ed;
				}
                else B2[++len2]=B[i];
            }
        }
		printf("\n");
        len=len2;
        for(int i=1;i<=len2;i++)B[i]=B2[i];
    }
    return 0;
}

#include<bits/stdc++.h>
using namespace std;
const int N=2e5+10;
struct Block{int st,ed;}B[N],B2[N];int len,len2;
int n,a[N],nxt[N];
int main()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++)scanf("%d",&a[i]);  a[n+1]=-1;
    for(int i=1;i<n;i++)if(a[i]==a[i+1])nxt[i]=i+1;else nxt[i]=0;
	len=0;
    for(int i=1,st=1;i<=n;i++)
    {
        if(a[i]!=a[i+1])
        {
            B[++len]={st,i};
            st=i+1;
        }
    }
    while(len)
    {
        len2=0;
        for(int i=1;i<=len;i++)
        {
            printf("%d ",B[i].st);
            B[i].st=nxt[B[i].st];
            if(B[i].st)
            {
                if(len2 && a[B2[len2].ed]==a[B[i].st])
				{
					nxt[B2[len2].ed]=B[i].st;
					B2[len2].ed=B[i].ed;
				}
                else B2[++len2]=B[i];
            }
        }
		printf("\n");
        len=len2;
        for(int i=1;i<=len2;i++)B[i]=B2[i];
    }
    return 0;
}