#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
int main() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
int N;
cin >> N;
if (N <= 2) {
cout << -1;
return 0;
}
int x[N+1], y[N+1];
for (int i = 1; i <= N; i++) cin >> x[i] >> y[i];
ll dx1 = x[2] - x[1], dy1 = y[2] - y[1];
ll dx2 = x[3] - x[1], dy2 = y[3] - y[1];
ll sx, sy;
if (dy1 == 0) {
sx = dx1;
} else if (dy2 == 0) {
sx = dx2;
} else {
ll GCD = gcd(dy1,dy2);
sx = dy1/GCD*dx1 + dy2/GCD*dx2;
}
if (dx1 == 0) {
sy = dy1;
} else if (dx2 == 0) {
sy = dy2;
} else {
ll GCD = gcd(dx1,dx2);
sy = dx1/GCD*dy1 + dx2/GCD*dy2;
}
if (sx == 0 || sy == 0) cout << -1;
else cout << abs(sx*sy);
return 0;
}
/*
3
1 1
1 3
3 2
5
0 0
1 0
-1 0
0 1
0 -1
1
1 -1
*/
