n = input()
n_list = n.split()
n_intlist = [int(s) for s in n_list]
#print(n_intlist)

lists = []
for i in range(n_intlist[0]):
    i = input()
    i_list = i.split()
    i_intlist = [int(s) for s in i_list]
    lists.extend(i_intlist)
    #print(lists)
    lists.sort()
    #print(lists)
    lists_str = [str(n) for n in lists]
#print(lists_str)
lists_count = len(lists_str)
i = 0
count = 0
while i < lists_count:
    print(lists_str[i],end="")
    i += 1
    count += 1
    if count % 5 == 0:
        print("")