#include <bits/stdc++.h>
using namespace std;

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);
 
    pair<int,int> P,Q,R;
    cin >> P.first >> P.second,P.first *= 2,P.second *= 2;
    cin >> Q.first >> Q.second,Q.first *= 2,Q.second *= 2;
    cin >> R.first >> R.second,R.first *= 2,R.second *= 2;
 
    auto dist = [&](int x1,int y1,int x2,int y2) -> int {return abs(x1-x2)+abs(y1-y2);};

    vector<pair<int,int>> answer;
    for(int i=-4000; i<=4000; i++) for(int k=-4000; k<=4000; k++){
        auto [x1,y1] = P;
        auto [x2,y2] = Q;
        auto [x3,y3] = R;
        int d1 = dist(x1,y1,i,k);
        int d2 = dist(x2,y2,i,k);
        int d3 = dist(x3,y3,i,k);
        if(d1 == d2 && d2 == d3){
            if(max(abs(i),abs(k)) > 2000){cout << "-1\n"; return 0;}
            answer.push_back({i,k});
        }    
    }
    cout << answer.size() << "\n";
    cout << fixed << setprecision(20);
    for(auto [x,y] : answer){
        cout << x/2.0 << " " << y/2.0 << "\n";
    }
    
}