n=int(raw_input())
n1=n//4
n2=n//7
s=0
flag=False
for i in range(n1+1):
    for j in range(n2+1):
        if i*4+j*7==n:
            flag=True
            break
    if flag:
        break
if flag:
    for k in range(i):
        s=s*10+4
    for k in range(j):
        s=s*10+7
    print s
else:
    print -1