#include <bits/stdc++.h>
using namespace std;
constexpr int MOD = 1000000007;
template <typename T>
std::istream& operator>>(std::istream& i, vector<T>& t) {
  for (auto& v : t) {
    i >> v;
  }
  return i;
}
template <typename T>
std::ostream& operator<<(std::ostream& o, const vector<T>& t) {
  for (size_t i = 0; i < t.size(); ++i) {
    o << t[i] << " \n"[i == t.size() - 1];
  }
  return o;
}
template <typename T>
using minheap = priority_queue<T, vector<T>, greater<T>>;
template <typename T>
using maxheap = priority_queue<T, vector<T>, less<T>>;
int logceil(long long first) {
  int b = 0;
  while (first) {
    first >>= 1;
    ++b;
  }
  return b;
}
namespace std {
template <typename T, typename U>
struct hash<pair<T, U>> {
  hash<T> t;
  hash<U> u;
  size_t operator()(const pair<T, U>& p) const {
    return t(p.first) ^ (u(p.second) << 7);
  }
};
}  // namespace std
template <typename T, typename F>
T bsh(T l, T h, const F& f) {
  T r = -1, m;
  while (l <= h) {
    m = (l + h) / 2;
    if (f(m)) {
      l = m + 1;
      r = m;
    } else {
      h = m - 1;
    }
  }
  return r;
}
template <typename T, typename F>
T bsl(T l, T h, const F& f) {
  T r = -1, m;
  while (l <= h) {
    m = (l + h) / 2;
    if (f(m)) {
      h = m - 1;
      r = m;
    } else {
      l = m + 1;
    }
  }
  return r;
}
template <typename T>
T gcd(T a, T b) {
  if (a < b) swap(a, b);
  return b ? gcd(b, a % b) : a;
}
template <typename T>
class vector2 : public vector<vector<T>> {
 public:
  vector2() {}
  vector2(size_t a, size_t b, T t = T())
      : vector<vector<T>>(a, vector<T>(b, t)) {}
};
template <typename T>
class vector3 : public vector<vector<vector<T>>> {
 public:
  vector3() {}
  vector3(size_t a, size_t b, size_t c, T t = T())
      : vector<vector<vector<T>>>(a, vector<vector<T>>(b, vector<T>(c, t))) {}
};
class B {
 public:
  bool check(int c4, int c7, int c47, int c74, bool put4, ostream& cout) {
    stringstream ss;
    while (true) {
      if (put4) {
        if (!c4) return false;
        ss << '4';
        --c4;
        while (c4 > c74) {
          ss << '4';
          --c4;
        }
        if (c47)
          --c47;
        else
          break;
      } else {
        if (!c7) return false;
        ss << '7';
        --c7;
        if (!c47)
          while (c7) {
            ss << '7';
            --c7;
          }
        if (c74)
          --c74;
        else
          break;
      }
      put4 = !put4;
    }
    if (c4 || c7 || c47 || c74) return false;
    cout << ss.str() << endl;
    return true;
  }
  void solve(istream& cin, ostream& cout) {
    int c4, c7, c47, c74;
    cin >> c4 >> c7 >> c47 >> c74;
    if (!check(c4, c7, c47, c74, true, cout) &&
        !check(c4, c7, c47, c74, false, cout))
      cout << -1 << endl;
  }
};
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(nullptr);
  cout.tie(nullptr);
  B solver;
  std::istream& in(std::cin);
  std::ostream& out(std::cout);
  solver.solve(in, out);
  return 0;
}
