#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 lowbit(int x) {
    return x & -x;
}

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];
        for (int j = 0; j <= A; j ++) {
            int t = 0;
            if (j >= a[i] && lowbit(j) >= a[i]) {
                t |= f[i - 1][j - a[i]];
            }
            if (A - j >= a[i] && lowbit(A - j) >= a[i]) {
                t |= f[i - 1][j];
            }
            f[i][j] = t;
        }
    }

    int J = -1;
    if (f[N][0]) J = 0;
    else if (A > 1 && f[N][A / 2]) J = A / 2;
    int JJ = J;
    if (J == -1) {
        printf("no\n");
        return 0;
    }
    for (int i = N; i >= 1; A -= a[i], i --) {
        if (!f[i][J]) {
            printf("gg f[i][J]=0\n");
            exit(0);
        }
        if (J >= a[i] && lowbit(J) >= a[i] && f[i - 1][J - a[i]]) {
            ans[i] = 'l', J -= a[i];
        } else if (A - J >= a[i] && lowbit(A - J) >= a[i] && f[i - 1][J]) {
            ans[i] = 'r';
        } else {
            printf("gg\n");
            exit(0);
        }
    }
    assert(strlen(ans + 1) == N);

    deque<int> q;
    for (int i = 1; i <= N; i ++) {
        int t = a[i];
        if (ans[i] == 'l') {
            for (; q.size() && q.front() == t; q.pop_front()) t *= 2;
            q.push_front(t);
        } else {
            for (; q.size() && q.back() == t; q.pop_back()) t *= 2;
            q.push_back(t);
        }
    }
    if (q.size() != 1) {
        A = 0;
        for (int i = 1; i <= N; i ++) A += a[i];
        printf("A=%d, JJ=%d, qs=%d\n", A, JJ, (int)q.size());
    }
    printf("%s\n", ans + 1);
    return 0;
}