import sys
sys.setrecursionlimit(10**6)
#input = sys.stdin.readline
fn=lambda:int(input())
f=lambda:input().split()
ff=lambda:map(int,input().split())
fff=lambda:list(map(int,input().split()))
from collections import Counter,deque,defaultdict
from itertools import combinations
import re
import math
ma=-float('inf')
mi=float('inf')
mod=10**9+7
dis=((1,0),(-1,0),(0,1),(0,-1))
#import numpy as np #pypyでは使えない
##############################################

n=fn()
c=fff()
ans=[]
for i,v in enumerate(c,1):
    if v!=0:
        ans.append(str(i)*v)
print(*sorted(ans,reverse=True),sep='')