#include<iostream>

#include<cstdio>

#include<cstring>

using namespace std;

int const maxn=;

int n,a[maxn],f[maxn],col[maxn],head[maxn],ct,pos[maxn];

bool flag;

struct N{

    int to,next;

    N(int t=,int n=):to(t),next(n) {}

}edge[maxn*maxn];

void add(int x,int y){edge[++ct]=N(y,head[x]); head[x]=ct;}

bool init()

{

    f[n]=n+;//!

    for(int i=n-;i;i--)

    {

        f[i]=min(a[i+],f[i+]);

        for(int j=i+;j<=n;j++)

            if(a[j]>a[i]&&f[j]<a[i])add(i,j),add(j,i);

    }

    return ;

}

void dfs(int x)

{

    for(int i=head[x];i;i=edge[i].next)

    {

        int u=edge[i].to;

        if(col[u]==col[x]){flag=; return;}

        else if(!col[u])col[u]=(col[x]^),dfs(u);

        if(flag)return;

    }

}

int main()

{

    scanf("%d",&n);

    for(int i=;i<=n;i++) scanf("%d",&a[i]);

    init();

    for(int i=;i<=n;i++)

        if(!col[i])

        {

            col[i]=;

            dfs(i);

            if(flag){printf("0\n"); return ;}

        }

    int nw=;

    for(int i=;i<=n;i++)

    {

        pos[a[i]]=col[i];

        if(col[i]==)printf("a ");

        else printf("c ");

        while(pos[nw])

        {

            if(pos[nw]==)printf("b ");

            else printf("d ");

            nw++;

        }

    }

    return ;

}