#include <cstdio>
#include <cstdlib>
#include <cstring>
inline int min(int a, int b)
{
    return a < b ? a : b;
}
struct
{
    int data[1001], ite;
} sta, stb;
typedef struct Edge
{
    int from, to;
    Edge *next;
    Edge(int f, int t, Edge *n) : from(f), to(t), next(n) {}
} * lpEdge;
lpEdge G[1001];
#define addEdge(x, y) G[(x)] = new Edge((x), (y), G[(x)])
int a[1001], n, S[1001], col[1001];
void color(int v)
{
    for (lpEdge cur = G[v]; cur; cur = cur->next)
        if (col[cur->to] == col[v])
            putchar('0'), exit(0);
        else if (col[cur->to] == -1)
            col[cur->to] = col[v] ^ 1, color(cur->to);
}
int main()
{
    memset(&sta, 0, sizeof(sta));
    memset(&stb, 0, sizeof(stb));
    memset(col, -1, sizeof(col));
    scanf("%d", &n);
    for (int i = 0; i < n; i++)
        scanf("%d", a + i);
    S[n] = 0x3f3f3f3f;
    for (int i = n - 1; i >= 0; i--) S[i] = min(a[i], S[i + 1]);
    for (int i = 0; i < n; i++)
        for (int j = i + 1; j < n; j++)
            if (a[i] < a[j] && S[j + 1] < a[i])
                addEdge(i, j), addEdge(j, i);
    for (int i = 0; i < n; i++)
        if (col[i] == -1) col[i] = 0, color(i);
    for (int i = 0, next = 1; i < n; i++)
    {
        if (col[i] == 0)
            sta.data[sta.ite++] = a[i], printf("a ");
        else
            stb.data[stb.ite++] = a[i], printf("c ");
        while (sta.data[sta.ite - 1] == next || stb.data[stb.ite - 1] == next)
        {
            if (sta.data[sta.ite - 1] == next) sta.ite--, printf("b "), next++;
            if (stb.data[stb.ite - 1] == next) stb.ite--, printf("d "), next++;
        }
    }
    return 0;
}