#include<bits/stdc++.h>
using namespace std;
#define debug(x) cout<<"["<<#x<<": "<<x<<"]\n"
#define debug2(x, y) cout<<"["<<#x<<": "<<x<<"]"<<"  ["<<#y<<": "<<y<<"]\n"
#define debug3(x, y, z) cout<<"["<<#x<<": "<<x<<"]"<<"  ["<<#y<<": "<<y<<"]"<<"  ["<<#z<<": "<<z<<"]\n"
#define debug4(x, y, z, k) cout<<"["<<#x<<": "<<x<<"]"<<"  ["<<#y<<": "<<y<<"]"<<"  ["<<#z<<": "<<z<<"]"<<"  ["<<#k<<": "<<k<<"]\n"
#define debug5(x, y, z, k, m) cout<<"["<<#x<<": "<<x<<"]"<<"  ["<<#y<<": "<<y<<"]"<<"  ["<<#z<<": "<<z<<"]"<<"  ["<<#k<<": "<<k<<"]"<<"  ["<<#m<<": "<<m<<"]\n"
#define debug6(x, y, z, k, m, n) cout<<"["<<#x<<": "<<x<<"]"<<"  ["<<#y<<": "<<y<<"]"<<"  ["<<#z<<": "<<z<<"]"<<"  ["<<#k<<": "<<k<<"]"<<"  ["<<#m<<": "<<m<<"]"<<"  ["<<#n<<": "<<n<<"]\n"

const int n = 4;

int poss1(vector<pair<int,int>> now, int w, int h) {
    assert(now.size() == 1);
    if(w <= 0 || h <= 0) return 0;
    if(now[0].first == w && now[0].second == h) return 1;
    if(now[0].second == w && now[0].first == h) return 1;
    return 0;
}

int poss2(vector<pair<int,int>> now, int w, int h) {
    assert(now.size() == 2);
    if(w <= 0 || h <= 0) return 0;
    for(int i=0; i<2; i++) {
        vector<pair<int,int>> pass;
        for(int j=0; j<2; j++) if(j != i) {
            pass.push_back(now[j]);
        }
        if(now[i].first == w) return poss1(pass, w, h - now[i].second);
        if(now[i].second == w) return poss1(pass, w, h - now[i].first);
        if(now[i].first == h) return poss1(pass, w-now[i].second, h);
        if(now[i].second == h) return poss1(pass, w-now[i].first, h);
    }
    return 0;
}

int poss3(vector<pair<int,int>> now, int w, int h) {
    assert(now.size() == 3);
    //debug2(w, h);
    if(w <= 0 || h <= 0) return 0;
    for(int i=0; i<3; i++) {
        vector<pair<int,int>> pass;
        for(int j=0; j<3; j++) if(j != i) {
            pass.push_back(now[j]);
        }
        if(now[i].first == w) return poss2(pass, w, h - now[i].second);
        if(now[i].second == w) return poss2(pass, w, h - now[i].first);
        if(now[i].first == h) return poss2(pass, w-now[i].second, h);
        if(now[i].second == h) return poss2(pass, w-now[i].first, h);
    }
    return 0;
}

int poss4(vector<pair<int,int>> a, int len) {
    assert(a.size() == 4);
    for(int i=0; i<n; i++) {
        vector<pair<int,int>> pass;
        for(int j=0; j<n; j++) if(j != i) {
            pass.push_back(a[j]);
        }
        if(a[i].first == len) return poss3(pass, len, len - a[i].second);
        if(a[i].second == len) return poss3(pass, len, len - a[i].first);
    }
    //debug(33);
    int ok = 0;
    //check the cases where above 2 block form a rectangle
    for(int i=0; i<n; i++) {
        for(int j=0; j<n; j++) if(j != i) {
            vector<pair<int,int>> pass;
            for(int k=0; k<n; k++) {
                if(k == i || k==j) continue;
                pass.push_back(a[k]);
            }

            for(int mask=0; mask<4; mask++) {
                vector<pair<int,int>> now = {a[i], a[j]};
                for(int at = 0; at < 2; at++) {
                    if((mask&(1<<at))) swap(now[at].first, now[at].second);
                }
                if(now[0].first + now[1].first == len && now[0].second == now[1].second) ok |= poss2(pass, len, len - now[0].second);
            }
        }
    }
    //above 2 doesnt form a rectangle
    for(int i=0; i<n; i++) {
        for(int j=0; j<n; j++) if(j != i) {
            for(int k=0; k<n; k++) if(k != i && k != j) {
                for(int l=0; l<n; l++) if(l != i && l !=j && l != k) {
                    for(int mask=0; mask < 16; mask++) {
                        vector<pair<int,int>> now = {a[i], a[j], a[k], a[l]};
                        for(int at = 0; at < n; at++) if((mask&(1<<at))) {
                            swap(now[at].first, now[at].second);
                        }
                        if(now[0].first + now[1].first == len
                            && now[0].first == now[2].first
                            && now[1].first == now[3].first
                            && now[0].second + now[2].second == len
                            && now[1].second + now[3].second == len) return 1;
                    }
                }
            }
        }
    }
    return ok;
}

int main() {
    vector<pair<int,int>> a(n);
    int area = 0;
    for(int i=0; i<n; i++) {
        cin>> a[i].first >> a[i].second;
        area += a[i].first * a[i].second;
    }
    int len = sqrt(area);
    while(len * len < area) len++;
    if(len*len > area) {
        cout<< 0 << endl;
        return 0;
    }
    //debug(len);
    if(poss4(a, len)) cout<< 1 << endl;
    else cout<< 0 << endl;

}