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