a = []
n=4;
for i in range(n+1):
  a.append(i+1)
  
def In(k): 
	for i in range(k):
		print(a[i])
	print()


def TapCon(k):	
	for i in range(0,k,1):
		a[i] = i + 1   
	In(k)			
	for i in range(k-1,-1,-1):	
		if (a[i] < n - k + i + 1):	
			a[i] = a[i] + 1  
			for j in range(i+1,k,1):
				a[j] = a[j - 1] + 1 	
			In(k)
			i = k  
      
TapCon(2)