#include <cstdio>
#include <iostream>
using namespace std;
const int N = 10005;
int a[N];
int main() {
	int n, sum = 0, c;
	scanf("%d", &n);
	for (int i = 0; i < n; i++)
		scanf("%d%d", &a[i], &a[i + n]);
	for (int i = 0; i < n; i++)
		sum += a[i] + a[i + n] - 8, c += sum;
	printf("%d", c);
	return 0;
}