#include<iostream>

#include<cstdio>

#include<cmath>

#include<cstdlib>

#include<cstring>

#include<algorithm>

using namespace std;

int read()

{

    int x=,f=;char c=getchar();

    while (c<''||c>'') {if (c=='-') f=-;c=getchar();}

    while (c>=''&&c<='') x=(x<<)+(x<<)+(c^),c=getchar();

    return x*f;

}

#define N 1010

int n,a[N],mn[N],fa[N<<],stk1[N],stk2[N],top1=,top2=,tot=,cur=;

char ans[N<<];

int find(int x){return fa[x]==x?x:fa[x]=find(fa[x]);}

void merge(int x,int y){fa[find(x+n)]=find(y),fa[find(y+n)]=find(x);}

int main()

{

#ifndef ONLINE_JUDGE

    freopen("stack.in","r",stdin);

    freopen("stack.out","w",stdout);

    const char LL[]="%I64d\n";

#else

    const char LL[]="%lld\n";

#endif

    n=read();

    for (int i=;i<=n;i++) a[i]=read();

    mn[n+]=n+;for (int i=n;i;i--) mn[i]=min(a[i],mn[i+]);

    for (int i=;i<=n+n;i++) fa[i]=i;

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

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

        if (a[i]<a[j]&&mn[j+]<a[i]) merge(i,j);

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

    {

        while (a[stk1[top1]]==cur+) cur++,ans[++tot]='b',top1--;

        bool flag=;

        for (int j=;j<=top1;j++) if (find(stk1[j]+n)==find(i)) {flag=;break;}

        for (int j=;j<=top2;j++) if (find(stk2[j])==find(i)) {flag=;break;}

        if (flag) stk1[++top1]=i,ans[++tot]='a';

        else

        {

            while (a[stk1[top1]]==cur+||a[stk2[top2]]==cur+)

            if (a[stk1[top1]]==cur+) cur++,ans[++tot]='b',top1--;

            else cur++,ans[++tot]='d',top2--;

            flag=;

            for (int j=;j<=top1;j++) if (find(stk1[j])==find(i)) {flag=;break;}

            for (int j=;j<=top2;j++) if (find(stk2[j]+n)==find(i)) {flag=;break;}

            if (flag) stk2[++top2]=i,ans[++tot]='c';

            else {cout<<;return ;}

        }

    }

    while (top1||top2)

    if (top1&&a[stk1[top1]]<a[stk2[top2]]||top2==) ans[++tot]='b',top1--;

    else ans[++tot]='d',top2--;

    for (int i=;i<=tot;i++) cout<<ans[i]<<' ';

    return ;

}