Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = []
Str = ''
for i in range(N):
    lst.append(input())
for k in range(N):
    for M in range(M-1):
        if lst[M] > lst[M+1]:
            lst[M],lst[M+1] = lst[M+1] , lst[M]
for j in range(N):
    Str += lst[j]
print(Str)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = []
Str = ''
for i in range(N):
    lst.append(input())
for k in range(N):
    for M in range(M-1):
        if lst[M] > lst[M+1]:
            lst[M],lst[M+1]  ==lst[M+1] , lst[M]
for j in range(N):
    Str += lst[j]
print(Str)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = []
Str = ''
for i in range(N):
    lst.append(input())
lst.sort()
for j in range(N):
    Str += Slst[j]
print(Str)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
Str = ''
for i in range(n):
    lst.append(input())
lst.sort()
for j in lst:
    Str += j
print(Str)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
Str = ''
for i in range(L):
    lst.append(input())
lst.sort()
for j in lst:
    Str += j
print(Str)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
Str = ''
for i in range(L):
    lst.append(input())
for k  in range(N):
    for j in range(N-1):
        if lst[j]+lst[j+1] >= lst[j+1]+lst[j]:
            lst[j],lst[j+1] = lst[j+1] ,lst[j]

for i in lst:
    Str += i
print(Str)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
Str = ''
for i in range(L):
    lst.append(input())
for k  in range(N):
    for j in range(N-1):
        if lst[j]+lst[j+1] >= lst[j+1]+lst[j]:
            lst[j],lst[j+1] = lst[j+1] ,lst[j]

for i in lst:
    Str += i
print(Str)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
Str = ''
for i in range(L):
    lst.append(input())
for k  in range(N):
    for j in range(N-1):
        if lst[j] >= lst[j+1]:
            lst[j],lst[j+1] = lst[j+1] ,lst[j]

for i in lst:
    Str += i
print(Str)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
Str = ''
for i in range(L):
    lst.append(input())
for k  in range(N):
    for j in range(N-1):
        if lst[j] >= lst[j+1]:
            lst[j],lst[j+1] = lst[j+1] ,lst[j]

for i in lst:
    Str += i
print(Str)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
Str = ''
for i in range(L):
    lst.append(input())
for k  in range(N):
    for j in range(N-1):
        if lst[j] >= lst[j+1]:
            lst[j],lst[j+1] = lst[j+1] ,lst[j]

for i in lst:
    Str += i
print(lst)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
lst2 = ''
for i in range(L):
    lst.append(input())
lst.sort()
#for k  in range(N):
#    for j in range(N-1):
#        if lst[j] > lst[j+1]:
#            lst[j],lst[j+1] = lst[j+1] ,lst[j]

for i in lst:
    lst2 += i
print(lst2)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
lst2 = ''
for i in range(L):
    lst.append(input())
lst.sort()
#for k  in range(N):
#    for j in range(N-1):
#        if lst[j] > lst[j+1]:
#            lst[j],lst[j+1] = lst[j+1] ,lst[j]

for i in range(L):
    lst2 += lst[i]
print(lst2)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
lst2 = ''
for i in range(L):
    lst.append(input())
for k  in range(N):
    for j in range(N-1):
        if lst[j] > lst[j+1]:
            lst[j],lst[j+1] = lst[j+1] ,lst[j]

for M in range(L):
    lst2 += lst[M]
print(lst2)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)

Buggy python submission (verdict: Runtime Error):
N , L= map(int,input().split())
lst = list()
lst2 = ''
for i in range(L):
    lst.append(input())
for k in range(N):
    for j in range(N-1):
        if lst[j] > lst[j+1]:
            lst[j],lst[j+1] = lst[j+1] ,lst[j]

for M in range(L):
    lst2 += lst[M]
print(lst2)


Fixed submission:
N,L=map(int, input().split())
S=[]
for i in range(N):
    S.append(input())
S.sort()
result=''
for j in range(N):
    result+=S[j]     
print(result)