n = eval(input())
ans = 1000
for x in range(101):
        for y in range(101):
                if (4 * x + 7 * y == n):
                        if x + y < ans:
                                ans = x + y
                                ansx = x
                                ansy = y
                        elif x + y == ans:
                                if x > ansx:
                                        ansx = x
                                        ansy = y
if ans == 1000:print("-1")
else:
        for i in range(ansx): print("4", end = "")
        for i in range(ansy): print("7", end = "")