t=int(input())
m=0
n=0
s=0
ys=t%7
m=t//7
if ys==0:
     print(m*"7")
elif ys==4:
   print("4",(m)*"7",sep="")
elif ys!=4 :
        i=1
        while i<=m :
            s=ys+i*7
            if s%4==0 :
                n=s//4
                print(n*"4",(m-i)*"7",sep="")
                break;
            i+=1
 
        if i>m :
           print("-1")