// ki bood ke goft Ghatinga?

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef pair<pii,int> ppiii;

// vectors and Sets:
#define vc vector
#define pb push_back
#define all(c) (c).begin(), (c).end()

// pairs
#define mp make_pair
#define fr first
#define sc second

// execution time check and Debug
#define StartEX clock_t startExeTime = clock();
#define EndEX clock_t endExeTime = clock();
#define ExTime cerr << "\nTotal Execution Time is: " << double(-double(startExeTime)+double(endExeTime)) / CLOCKS_PER_SEC;
#define debug(x) cerr << #x << " : " << x << '\n'
#define endl "\n"

// time optimization
#define Heh ios::sync_with_stdio(false);cin.tie(0);
#define Bah ios::sync_with_stdio(false);
#pragma GCC optimize("Ofast")
// #pragma GCC target("avx,avx2,fma")

// useful functions
ll pw(ll a,ll b){
  ll ret = 1;
  ll mul = a;
  while(b > 0){
	if(b&1)
	  ret = (ret * mul);
	mul = (mul * mul);
	b >>= 1;
  }
  return ret;
}
ll pw(ll a,ll b,ll mod){
  ll ret = 1;
  ll mul = a;
  while(b > 0){
	if(b&1)
	  ret = (ret * mul) % mod;
	mul = (mul * mul) % mod;
	b >>= 1;
  }
  return ret;
}

ll to_int(string s){
  ll ret = 0;
  for(int i = 0 ; i < (int)s.size() ; i++) ret = 10 * ret + s[i] - '0';
  return ret;
}

bool deq(ld a , ld b){return (abs(a-b) < 0.000001);} // 10 ^ -6

const int MAXP = 1e6 + 16;

int can2(int a , int b , vc<pii> p){
  if((p[0].fr == a and p[1].fr == a)) return 1;
  if((p[0].fr == a and p[1].sc == a)) return 1;
  if((p[0].sc == a and p[1].fr == a)) return 1;
  if((p[0].sc == a and p[1].sc == a)) return 1;

  if((p[0].fr == b and p[1].fr == b)) return 1;
  if((p[0].fr == b and p[1].sc == b)) return 1;
  if((p[0].sc == b and p[1].fr == b)) return 1;
  if((p[0].sc == b and p[1].sc == b)) return 1;

  return 0;
}

int can3(int a , int b , vc<pii> p){
  for(int i = 0 ; i < 3 ; i++){
    vc<pii> pp;
    for(int j = 0 ; j < 3 ; j++){
      if(j != i) pp.pb(p[j]);
    }
    if(p[i].fr == a and can2(a , b - p[i].sc , pp)) return 1;
    if(p[i].sc == a and can2(a , b - p[i].fr , pp)) return 1;
    if(p[i].fr == b and can2(a - p[i].sc , b , pp)) return 1;
    if(p[i].sc == b and can2(a - p[i].fr , b , pp)) return 1;
  }
  return 0;
}

int main()
{
  int a[4] , b[4];
  for(int i = 0 ; i < 4 ; i++){
    cin >> a[i] >> b[i];
    if(a[i] < b[i]) swap(a[i] , b[i]);
  }
  int s = 0;
  for(int i = 0 ; i < 4 ; i++) s += a[i] * b[i];
  int sq = sqrt(s);
  for(int i = sq-1 ; i <= sq+1 ; i++){
    if(i * i == s){
      sq = i;
      break;
    }
  }
  if(sq * sq != s){
    cout << 0 << endl;
    return 0;
  }
  int cnt = 0;
  for(int i = 0 ; i < 4 ; i++){
    if(a[i] > sq){
      cnt = -1;
      break;
    }
    if(a[i] == sq) cnt++;
  }
  if(cnt == -1){
    cout << 0 << endl;
    return 0;
  }
  if(cnt == 4){
    cout << 1 << endl;
    return 0;
  }
  if(cnt == 3){
    cout << 0 << endl;
    return 0;
  }
  if(cnt == 2){
    vc<pii> rm;
    int rms = sq;
    for(int i = 0 ; i < 4 ; i++){
      if(a[i] == sq) rms -= b[i];
      else rm.pb({a[i] , b[i]});
    }
    cout << can2(sq , rms , rm) << endl;
    return 0;
  }
  if(cnt == 1){
    vc<pii> rm;
    int rms = sq;
    for(int i = 0 ; i < 4 ; i++){
      if(a[i] == sq) rms -= b[i];
      else rm.pb({a[i] , b[i]});
    }
    cout << can3(sq , rms , rm) << endl;
    return 0;
  }
  if(cnt == 0){
    int f = 0;
    vc<int> p = {0 , 1 , 2 , 3};
    do{
      if(((a[p[0]] == a[p[1]] and b[p[0]] + b[p[1]] == sq) or
	  (a[p[0]] == b[p[1]] and b[p[0]] + a[p[1]] == sq) or
	  (b[p[0]] == a[p[1]] and a[p[0]] + b[p[1]] == sq) or
	  (b[p[0]] == b[p[1]] and a[p[0]] + a[p[1]] == sq)) and
	 ((a[p[2]] == a[p[3]] and b[p[2]] + b[p[3]] == sq) or
	  (a[p[2]] == b[p[3]] and b[p[2]] + a[p[3]] == sq) or
	  (b[p[2]] == a[p[3]] and a[p[2]] + b[p[3]] == sq) or
	  (b[p[2]] == b[p[3]] and a[p[2]] + a[p[3]] == sq))) f = 1;
    }while(next_permutation(all(p)));
    cout << f << endl;
    return 0;
  }
}

// ki seda kard Patinga?