#include <bits/stdc++.h>
using namespace std;
string ans = "";
int h, t, b1, b2, b3;
void ss() {
  string st = "";
  if (h) st += '7';
  for (int i = 0; i < b1; ++i) st += '4';
  for (int i = 0; i < b2; ++i) st += "74";
  for (int i = 0; i < b3; ++i) st += '7';
  if (t) st += '4';
  if (ans == "" || ans > st) ans = st;
}
int main() {
  int a1, a2, a3, a4;
  cin >> a1 >> a2 >> a3 >> a4;
  for (h = 0; h <= 1; ++h)
    for (t = 0; t <= 1; ++t) {
      b2 = a3 - 1;
      b1 = a1 - b2 - t;
      b3 = a2 - b2 - h;
      if (b2 + h + t == a4 && b1 > 0 && b3 > 0) ss();
      b2 = a3;
      b1 = a1 - b2 - t;
      b3 = a2 - b2 - h;
      if ((b2 + h == a4 && b1 > 0 && b3 == 0) ||
          (b2 + t == a4 && b1 == 0 && b3 > 0))
        ss();
      b2 = a3 + 1;
      b1 = a1 - b2 - t;
      b3 = a2 - b2 - h;
      if (b2 == a4 && b1 == 0 && b3 == 0) ss();
    }
  if (ans == "") {
    cout << -1;
  } else {
    cout << ans;
  }
}
