#include <bits/stdc++.h>
using namespace std;
int c4, c7, c47, c74;
void solve1() {
  for (int i = 0; i < c4 - c74 - 1; i++) cout << 4;
  for (int i = 0; i < c74; i++) cout << 47;
  for (int i = 0; i < c7 - c74; i++) cout << 7;
  cout << 4;
}
void solve2() {
  cout << 7;
  for (int i = 0; i < c4 - c74; i++) cout << 4;
  for (int i = 0; i < c74; i++) cout << 47;
  for (int i = 0; i < c7 - c74 - 1; i++) cout << 7;
}
int main() {
  cin >> c4 >> c7 >> c47 >> c74;
  if (c47 == c74) {
    if (c4 >= c74 + 1 && c7 >= c74) {
      solve1();
    } else if (c4 == c74 && c7 >= c74 + 1)
      solve2();
    else
      cout << -1;
  } else if (c47 == c74 + 1) {
    if (c4 >= c47 && c7 >= c47) {
      for (int i = 0; i < c4 - c47; i++) cout << 4;
      for (int i = 0; i < c47; i++) cout << 47;
      for (int i = 0; i < c7 - c47; i++) cout << 7;
    } else
      cout << -1;
  } else if (c74 == c47 + 1) {
    if (c4 >= c74 && c7 >= c74) {
      cout << 74;
      for (int i = 0; i < c4 - c74; i++) cout << 4;
      for (int i = 0; i < c74 - 2; i++) cout << 74;
      for (int i = 0; i < c7 - c74; i++) cout << 7;
      cout << 74;
    } else
      cout << -1;
  } else
    cout << -1;
  return 0;
}
