#include <bits/stdc++.h>
using namespace std;
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  cout.tie(NULL);
  long long n;
  cin >> n;
  long long now = 0;
  long long mx = -1;
  while (true) {
    long long rem = (n - (now * 7));
    if (rem < 0) {
      break;
    } else {
      if (rem % 4 == 0) {
        mx = max(mx, now);
      }
    }
    now++;
  }
  if (mx == -1) {
    cout << -1;
    return 0;
  } else {
    long long four = n - (mx * 7);
    four /= 4;
    for (long long i = 0; i < four; i++) {
      cout << 4;
    }
    for (long long i = 0; i < mx; i++) {
      cout << 7;
    }
  }
}
