Missing Vertex in Parallelogram

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

int main ()
{
    int x[4], y[4];
    for (int i = 0; i < 3; i++)
        cin >> x[i] >> y[i];

    int a = abs(y[0]-y[1]);
    int b = abs(x[1]-x[0]);

    cout << x[2]-b << " " << y[2]-a << endl;
    return 0;
}