#include <cassert>
#include <cmath>
#include <cstdint>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <bitset>
#include <complex>
#include <deque>
#include <functional>
#include <iostream>
#include <limits>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <unordered_map>
#include <unordered_set>
#include <utility>
#include <vector>

using namespace std;

using Int = long long;

template <class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &a) { return os << "(" << a.first << ", " << a.second << ")"; };
template <class T> ostream &operator<<(ostream &os, const vector<T> &as) { const int sz = as.size(); os << "["; for (int i = 0; i < sz; ++i) { if (i >= 256) { os << ", ..."; break; } if (i > 0) { os << ", "; } os << as[i]; } return os << "]"; }
template <class T> void pv(T a, T b) { for (T i = a; i != b; ++i) cerr << *i << " "; cerr << endl; }
template <class T> bool chmin(T &t, const T &f) { if (t > f) { t = f; return true; } return false; }
template <class T> bool chmax(T &t, const T &f) { if (t < f) { t = f; return true; } return false; }



int main() {
  int A[4], B[4];
  for (; ; ) {
    for (int i = 0; i < 4; ++i) {
      if (!~scanf("%d%d", &A[i], &B[i])) {
        return 0;
      }
    }
    
    vector<pair<int, int>> dp[1 << 4];
    for (int i = 0; i < 4; ++i) {
      dp[1 << i].emplace_back(A[i], B[i]);
      dp[1 << i].emplace_back(B[i], A[i]);
    }
    for (int p = 0; p < 1 << 4; ++p) {
      for (int q = p; --q &= p; ) {
        for (const auto &r0 : dp[q]) for (const auto &r1 : dp[p - q]) {
          if (r0.first == r1.first) {
            dp[p].emplace_back(r0.first, r0.second + r1.second);
          }
          if (r0.second == r1.second) {
            dp[p].emplace_back(r0.first + r1.first, r0.second);
          }
        }
      }
    }
    int ans = 0;
    for (const auto &r : dp[15]) {
      if (r.first == r.second) {
        ans = 1;
      }
    }
    printf("%d\n", ans);
  }
  return 0;
}