#include <bits/stdc++.h>
using namespace std;
void OJ() {}
void solve() {
  long long n;
  cin >> n;
  long long digit = 1000000, a = -1, b = -1;
  for (long long i = 0; i < 1e6; ++i) {
    if (n >= 4 * i)
      if ((n - 4 * i) % 7 == 0) {
        if ((n - 4 * i) / 7 + i <= digit)
          digit = (n - 4 * i) / 7 + i, a = i, b = (n - 4 * i) / 7;
      }
  }
  if (a == -1) {
    cout << -1;
    return;
  }
  for (long long i = 0; i < a; ++i) cout << 4;
  for (long long i = 0; i < b; ++i) cout << 7;
}
signed main() {
  OJ();
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  solve();
}
