n=int(raw_input())
if n <4:
	print "-1"
else:
	a=n//7
	for i in range(a,-1,-1):
		if (n-7*i)%4==0:
			print "4"*((n-7*i)/4)+"7"*i
			break;
	
	if (n-7*i)%4!=0:
		print "-1"