#include <bits/stdc++.h>

using namespace std;

typedef long long i64;
const int BUFFER_SIZE = 1 << 20;
char rb[BUFFER_SIZE], *rp = rb, *rt = rb;
inline char read_char() {
    return rp == rt ? (rt = rb + fread(rb, 1, BUFFER_SIZE, stdin), rp = rb, *rp ++) : *rp ++;
}
inline i64 read_int() {
    i64 x = 0;
    char ch = read_char(), flag = 0;
    while (ch != '-' && (ch < '0' || ch > '9')) {
        ch = read_char();
    }
    if (ch == '-') {
        flag = 1;
        ch = read_char();
    }
    for (x = 0; ch >= '0' && ch <= '9'; ch = read_char()) {
        x = x * 10 + (ch - '0');
    }
    return flag ? -x : x;
}

const int MAX_N = 1000 + 5;
const int MAX_A = 1 << 13 | 5;

int N, A;
int a[MAX_N];
bitset<MAX_A> f[MAX_N];
char ans[MAX_N];

int main() {
    scanf("%d", &N);
    for (int i = 1; i <= N; i ++) {
        scanf("%d", &a[i]);
        A += a[i];
    }
    if (A & A - 1) {
        printf("no\n");
        return 0;
    }
    A = 0;
    f[0][0] = 1;
    for (int i = 1; i <= N; i ++) {
        A += a[i];
        // printf("f[%d]=", i);
        for (int j = 0; j <= A; j ++) {
            int t = 0;
            if ((j & -j) >= a[i]) {
                t |= f[i - 1][j - a[i]];
            }
            if ((A - j & j - A) >= a[i]) {
                t |= f[i - 1][j];
            }
            f[i][j] = t;
            // printf("%d", t);
        }
        // printf("\n");
    }
    if (f[N].none()) {
        printf("no\n");
        return 0;
    }
    int J = -1;
    for (int j = 0; j <= A; j += A / 2) {
        if (f[N][j]) {
            J = j;
            break;
        }
    }
    for (int i = N; i >= 1; A -= a[i], i --) {
        // printf("i=%d, J=%d\n", i, J);
        if ((J & -J) >= a[i] && f[i - 1][J - a[i]]) {
            ans[i] = 'l', J -= a[i];
        } else {
            ans[i] = 'r';
        }
    }
    printf("%s\n", ans + 1);
    return 0;
}