n=int(input())
sr=input().split()
a=[0 for i in range(n)]
for i in range(n):
    a[i]=int(sr[i])
k=0
k1=[0]
k1[0]=a[0]
k2=["1:"]
k2[0]=k2[0]+str(a[0])
for i in range(1,n):
    f=1
    for j in range(k+1):
        if(a[i]<k1[j]):
            f=0
            break
    if(f==1):
        k=k+1
        k1.append(a[i])
        k2.append(str(k+1)+":"+str(a[i]))
    else:
        k1[j]=a[i]
        k2[j]=k2[j]+" "+str(a[i])
print(k+1)
for i in range(k+1):
    print(k2[i])
/**************************************************************
	Problem: 1375
	User: admin
	Language: Python
	Result: Accepted
	Time:138 ms
	Memory:34480 kb
****************************************************************/