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