n = int(raw_input())
k = 0
d = 0
for i in range(n//7+1,-1,-1):
	for j in range(0,n//4+1):
		if i*7+j*4==n:
			k = i
			d = j
			break;
	if i*7+j*4==n:
		break;	

if k==0 and d==0:
	print "-1"
else:
	print "4"*d+"7"*k