n=int(input())
s=n//7
f=0
i,j=0,0
if (n-7*s)%4 ==0:
    f=(n-7*s)//4
else:
    while s>=0:
        s=s-1
        if (n-7*s)%4 == 0:
            f=(n-7*s)//4
            break
    if s == -1 or n == 0:
        print("-1")
for i in range(0,f):
    print("4",end='')
for j in range(0,s):
    print("7",end='')