import sys
from collections import deque,defaultdict
import itertools
import heapq
import bisect
import math

#sys.setrecursionlimit(10 ** 9)
input = lambda: sys.stdin.readline().rstrip()
ii = lambda: int(input())
mi = lambda: map(int, input().split())
ml = lambda: map(str, input().split())
li = lambda: list(mi())
li_st = lambda: list(map(str, input().split()))
lli = lambda n: [li() for _ in range(n)]
mod = 998244353

T = ii()
for i in range(T):
    M = ii()
    D = li()
    s = []
    for i in range(9):
        for j in range(D[i]):
            s.append(str(i+1))
    num = "".join(s)
    num = int(num)
    print(num*M)