#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int t = n % 4;
  int a = 0;
  for (int i = 0; i < 4; i++) {
    if ((i * 7) % 4 == t) a = i;
  }
  int b = -1, c;
  for (int j = (n - a) / 4 * 4 + a; j >= a; j -= 4) {
    if ((n - 7 * j) % 4 == 0 && (n - 7 * j >= 0)) {
      c = j;
      b = (n - 7 * j) / 4;
      break;
    }
  }
  if (b == -1) {
    cout << -1;
    return 0;
  }
  for (int i = 0; i < b; i++) cout << 4;
  for (int i = 0; i < c; i++) cout << 7;
  return 0;
}
