Buggy python submission (verdict: Runtime Error):
# -*- coding: utf-8 -*-
"""
Created on Sat Feb 16 19:31:10 2019
ABC118D
@author: maezawa
"""
import copy

n, m = list(map(int, input().split()))
a = list(map(int, input().split()))

nmatch = [2,5,5,4,5,6,3,7,6]
rmatch = list(reversed(nmatch))
nmdic = dict([(i+1,nmatch[i]) for i in range(9)])
#nums = [[],[],[1],[7],[4],[2,3,5],[6,9],[8]]
nums = [[] for _ in range(10)]
for  i in a:
    nums[nmdic[i]].append(i)
        
#print(nmdic)
#print(nums)

dp = [[-1,[]] for _ in range(n+1)]
dp[0] = [0, []]
#print(dp)

for i in range(1, n+1):
    cnds = []
    for j in range(2, 8):
        if nums[j] == []:
            continue
        if dp[i-j][0] == -1:
            continue
        cndo = dp[i-j][0]+1
        cndos = copy.copy(dp[i-j][1])
        cndos.append(max(nums[j]))
        cnds.append([cndo, cndos])
        #print(i, i-j, cnds, cndos)
    if cnds == []:
        continue
    dp[i] = max(cnds, key=lambda x: x[0])

ans = ''.join(map(str, sorted(dp[n][1], reverse=True)))
print(ans)



Fixed submission:
# -*- coding: utf-8 -*-
"""
Created on Sat Feb 16 19:31:10 2019
ABC118D
@author: maezawa
"""
import copy

n, m = list(map(int, input().split()))
a = list(map(int, input().split()))
a.sort(reverse=True)

nmatch = [2,5,5,4,5,6,3,7,6]
rmatch = list(reversed(nmatch))
nmdic = dict([(i+1,nmatch[i]) for i in range(9)])
#nums = [[],[],[1],[7],[4],[2,3,5],[6,9],[8]]
nums = [[] for _ in range(10)]
for  i in a:
    nums[nmdic[i]].append(i)
        
#print(nmdic)
#print(nums)

dp = [[-1,[]] for _ in range(n+1)]
dp[0] = [0, []]
#print(dp)

for i in range(1, n+1):
    cnds = []
    for k in a:
        j = nmdic[k]
        if i-j < 0:
            continue
        if dp[i-j][0] == -1:
            continue
        cndo = dp[i-j][0]+1
        cndos = copy.copy(dp[i-j][1])
        cndos.append(max(nums[j]))
        cnds.append([cndo, cndos])
        #print(i, i-j, cnds, cndos)
    if cnds == []:
        continue
    dp[i] = max(cnds, key=lambda x: x[0])

ans = ''.join(map(str, sorted(dp[n][1], reverse=True)))
print(ans)

Buggy python submission (verdict: Runtime Error):
# -*- coding: utf-8 -*-
"""
Created on Sat Feb 16 19:31:10 2019
ABC118D
@author: maezawa
"""
import copy

n, m = list(map(int, input().split()))
a = list(map(int, input().split()))

nmatch = [2,5,5,4,5,6,3,7,6]
rmatch = list(reversed(nmatch))
nmdic = dict([(i+1,nmatch[i]) for i in range(9)])
#nums = [[],[],[1],[7],[4],[2,3,5],[6,9],[8]]
nums = [[] for _ in range(10)]
for i in range(10):
    if i in a:
        nums[nmdic[i]].append(i)
        
#print(nmdic)
#print(nums)

dp = [[-1,[]] for _ in range(n+1)]
dp[0] = [0, []]
#print(dp)

for i in range(1, n+1):
    maxorder = 0
    cnds = []
    for j in range(1, 7):
        if nums[j] == []:
            continue
        if dp[i-j][0] == -1:
            continue
        cndo = dp[i-j][0]+1
        cndos = copy.copy(dp[i-j][1])
        cndos.append(max(nums[j]))
        cnds.append([cndo, cndos])
        #print(i, i-j, cnds, cndos)
    if cnds == []:
        continue
    dp[i] = max(cnds, key=lambda x: x[0])

ans = ''.join(map(str, sorted(dp[n][1], reverse=True)))
print(ans)



Fixed submission:
# -*- coding: utf-8 -*-
"""
Created on Sat Feb 16 19:31:10 2019
ABC118D
@author: maezawa
"""
import copy

n, m = list(map(int, input().split()))
a = list(map(int, input().split()))
a.sort(reverse=True)

nmatch = [2,5,5,4,5,6,3,7,6]
rmatch = list(reversed(nmatch))
nmdic = dict([(i+1,nmatch[i]) for i in range(9)])
#nums = [[],[],[1],[7],[4],[2,3,5],[6,9],[8]]
nums = [[] for _ in range(10)]
for  i in a:
    nums[nmdic[i]].append(i)
        
#print(nmdic)
#print(nums)

dp = [[-1,[]] for _ in range(n+1)]
dp[0] = [0, []]
#print(dp)

for i in range(1, n+1):
    cnds = []
    for k in a:
        j = nmdic[k]
        if i-j < 0:
            continue
        if dp[i-j][0] == -1:
            continue
        cndo = dp[i-j][0]+1
        cndos = copy.copy(dp[i-j][1])
        cndos.append(max(nums[j]))
        cnds.append([cndo, cndos])
        #print(i, i-j, cnds, cndos)
    if cnds == []:
        continue
    dp[i] = max(cnds, key=lambda x: x[0])

ans = ''.join(map(str, sorted(dp[n][1], reverse=True)))
print(ans)

Buggy python submission (verdict: Runtime Error):
# -*- coding: utf-8 -*-
"""
Created on Sat Feb 16 19:31:10 2019
ABC118D
@author: maezawa
"""

n, m = list(map(int, input().split()))
a = list(map(int, input().split()))

nmatch = [2,5,5,4,5,6,3,7,6]
rmatch = list(reversed(nmatch))

a_n = [(ai, nmatch[ai-1]) for ai in a]
a_n.sort(key = lambda x: x[0], reverse=True)
a_n.sort(key = lambda x: x[1])
a_n2 = [ai[1] for ai in a_n]
#print(a_n)

for j in range(1, m):
    number = a_n[0][0]
    n_order = n // a_n[0][1] - j
    rem = n % a_n[0][1] + a_n[0][1]*j
    ans = str(number) * n_order
    
    if rem in a_n2:
        one = a_n[a_n2.index(rem)][0]
        if number > one:
            ans = ans+str(one)
        else:
            ans = str(one)+ans
        break
            
print(ans)




Fixed submission:
# -*- coding: utf-8 -*-
"""
Created on Sat Feb 16 19:31:10 2019
ABC118D
@author: maezawa
"""
import copy

n, m = list(map(int, input().split()))
a = list(map(int, input().split()))
a.sort(reverse=True)

nmatch = [2,5,5,4,5,6,3,7,6]
rmatch = list(reversed(nmatch))
nmdic = dict([(i+1,nmatch[i]) for i in range(9)])
#nums = [[],[],[1],[7],[4],[2,3,5],[6,9],[8]]
nums = [[] for _ in range(10)]
for  i in a:
    nums[nmdic[i]].append(i)
        
#print(nmdic)
#print(nums)

dp = [[-1,[]] for _ in range(n+1)]
dp[0] = [0, []]
#print(dp)

for i in range(1, n+1):
    cnds = []
    for k in a:
        j = nmdic[k]
        if i-j < 0:
            continue
        if dp[i-j][0] == -1:
            continue
        cndo = dp[i-j][0]+1
        cndos = copy.copy(dp[i-j][1])
        cndos.append(max(nums[j]))
        cnds.append([cndo, cndos])
        #print(i, i-j, cnds, cndos)
    if cnds == []:
        continue
    dp[i] = max(cnds, key=lambda x: x[0])

ans = ''.join(map(str, sorted(dp[n][1], reverse=True)))
print(ans)