#include <bits/stdc++.h>
using namespace std;
long long n, so7, so4, kiemtra7;
bool check = true;
int main() {
  cin >> n;
  if (n % 7 == 0) {
    so7 = n / 7;
    for (int i = 1; i <= so7; i++) cout << "7";
  } else {
    int r = n % 4;
    if (r == 0) {
      kiemtra7 = (n - 4) / 28;
      if (kiemtra7 == 0) {
        check = false;
      } else {
        so7 = (((n - 4) / 7) / 4 * 4);
        n = n - so7 * 7;
        so4 = n / 4;
        for (int i = 1; i <= so4; i++) cout << "4";
        for (int i = 1; i <= so7; i++) cout << "7";
      }
      if (check == false) {
        so4 = n / 4;
        for (int i = 1; i <= so4; i++) cout << "4";
      }
    }
    if (r == 1) {
      kiemtra7 = (n - 4) / 7 - 3;
      so7 = ((((n - 4) / 7 - 3) / 4) * 4 + 3);
      n = n - so7 * 7;
      if (kiemtra7 < 0)
        cout << "-1";
      else {
        so4 = n / 4;
        for (int i = 1; i <= so4; i++) cout << "4";
        for (int i = 1; i <= so7; i++) cout << "7";
      }
    }
    if (r == 2) {
      kiemtra7 = (n - 4) / 7 - 2;
      so7 = ((((n - 4) / 7 - 2) / 4) * 4 + 2);
      n = n - so7 * 7;
      if (kiemtra7 < 0)
        cout << "-1";
      else {
        so4 = n / 4;
        for (int i = 1; i <= so4; i++) cout << "4";
        for (int i = 1; i <= so7; i++) cout << "7";
      }
    }
    if (r == 3) {
      kiemtra7 = (n - 4) / 7 - 1;
      so7 = ((((n - 4) / 7 - 1) / 4) * 4 + 1);
      n = n - so7 * 7;
      if (kiemtra7 < 0)
        cout << "-1";
      else {
        so4 = n / 4;
        for (int i = 1; i <= so4; i++) cout << "4";
        for (int i = 1; i <= so7; i++) cout << "7";
      }
    }
  }
}
