#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  scanf("%d", &n);
  int ans = -1;
  int sum = 7;
  int i = 1;
  while (sum <= n) {
    int y = n - sum;
    if (y % 4 == 0) ans = i;
    sum += 7;
    i++;
  }
  if (ans != -1) {
    int s = 7 * ans;
    int y = n - s;
    int x = y / 4;
    while (x--) {
      cout << "4";
    }
    while (ans--) {
      cout << "7";
    }
    return 0;
  }
  if (n % 7 == 0) {
    int x = n / 7;
    while (x--) cout << "7";
    return 0;
  }
  if (n % 4 == 0) {
    int x = n / 4;
    while (x--) cout << "4";
    return 0;
  }
  cout << "-1";
  return 0;
}
