num=int(input())
a=1
while True:
if num%7==0:
d=num//7
print('7'*d)
break
else:
b=num-4*a
if b%7==0:
c=b//7
print('4'*a+'7'*c)
break
elif b==4:
print('4'*(a+1))
break
elif b<4:
print('-1')
break
else:
a+=1
983. Minimum Cost For Tickets | 973. K Closest Points to Origin |
969. Pancake Sorting | 967. Numbers With Same Consecutive Differences |
957. Prison Cells After N Days | 946. Validate Stack Sequences |
921. Minimum Add to Make Parentheses Valid | 881. Boats to Save People |
497. Random Point in Non-overlapping Rectangles | 528. Random Pick with Weight |
470. Implement Rand10() Using Rand7() | 866. Prime Palindrome |
1516A - Tit for Tat | 622. Design Circular Queue |
814. Binary Tree Pruning | 791. Custom Sort String |
787. Cheapest Flights Within K Stops | 779. K-th Symbol in Grammar |
701. Insert into a Binary Search Tree | 429. N-ary Tree Level Order Traversal |
739. Daily Temperatures | 647. Palindromic Substrings |
583. Delete Operation for Two Strings | 518. Coin Change 2 |
516. Longest Palindromic Subsequence | 468. Validate IP Address |
450. Delete Node in a BST | 445. Add Two Numbers II |
442. Find All Duplicates in an Array | 437. Path Sum III |