#include <bits/stdc++.h>
using namespace std;
int s4, s7, s47, s74;
int main() {
  cin >> s4 >> s7 >> s47 >> s74;
  if (abs(s47 - s74) > 1 || s4 < s47 || s4 < s74 || s7 < s74 || s7 < s47 ||
      (s4 == s7 && s7 == s47 && s47 == s74)) {
    cout << -1 << endl;
    return 0;
  }
  if (s47 == s74 && min(s4, s7) == s47 && s7 > s4) {
    for (int i = 1; i <= s47; i++) cout << 74;
    for (int i = 1; i <= s7 - s47; i++) cout << 7;
  } else if (s47 == s74) {
    for (int i = 1; i <= s4 - s47; i++) cout << 4;
    for (int i = 1; i <= s47 - 1; i++) cout << 74;
    for (int i = 1; i <= s7 - s74 + 1; i++) cout << 7;
    cout << 4;
  }
  if (s47 > s74) {
    for (int i = 1; i <= s4 - s47; i++) cout << 4;
    for (int i = 1; i <= s47; i++) cout << 47;
    for (int i = 1; i <= s7 - s47; i++) cout << 7;
  }
  if (s47 < s74 && s4 == s74) {
    cout << 7;
    for (int i = 1; i <= s4 - s74 - 1; i++) cout << 4;
    for (int i = 1; i <= s74 - 1; i++) cout << 47;
    for (int i = 1; i <= s7 - s74; i++) cout << 7;
    cout << 4;
  } else if (s47 < s74) {
    cout << 74;
    for (int i = 1; i <= s4 - s74 - 1; i++) cout << 4;
    for (int i = 1; i <= s74 - 1; i++) cout << 47;
    for (int i = 1; i <= s7 - s74; i++) cout << 7;
    cout << 4;
  }
  return 0;
}
