n = int(input())
for i in range(n // 7 + 1):
for j in range((n - 7 * (n // 7 - i)) // 4 + 1):
if (n // 7 - i) * 7 + j * 4 == n:
print("4" * j + "7" * (n // 7 - i))
quit()
elif (n // 7 - i) * 7 + j * 4 > n:
break
print(-1)#include <bits/stdc++.h>
using namespace std;
int main()
{
ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);
int n;
cin>>n;
string ans = "";
while(n >= 7 && n%4 != 0){
n-=7;
ans+='7';
}
if(n%4 != 0){
cout<<-1<<'\n';
exit(0);
}
while(n >= 28){
n-=28;
ans+="7777";
}
while(n != 0){
n-=4;
ans+='4';
}
sort(ans.begin(), ans.end());
cout<<ans<<'\n';
}810A - Straight A | 1433C - Dominant Piranha |
633A - Ebony and Ivory | 1196A - Three Piles of Candies |
299A - Ksusha and Array | 448B - Suffix Structures |
1092B - Teams Forming | 1166C - A Tale of Two Lands |
544B - Sea and Islands | 152B - Steps |
1174D - Ehab and the Expected XOR Problem | 1511A - Review Site |
1316A - Grade Allocation | 838A - Binary Blocks |
1515D - Phoenix and Socks | 1624D - Palindromes Coloring |
1552F - Telepanting | 1692G - 2Sort |
1191A - Tokitsukaze and Enhancement | 903A - Hungry Student Problem |
52B - Right Triangles | 1712A - Wonderful Permutation |
1712D - Empty Graph | 1712B - Woeful Permutation |
1712C - Sort Zero | 1028B - Unnatural Conditions |
735B - Urbanization | 746C - Tram |
1278B - A and B | 1353D - Constructing the Array |