n=int(input())
b=-1
for i in range(0,n//4+1):
    a=n-i*4
    if a%7==0:
        b=int(a/7)
        break
if b==-1:print(b)
else:
    for j in range(0,i):print(4,end="")
    for j in range(0,b):print(7,end="")