#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll oo = 1LL<<60;

int main(void) {
    int n;
    scanf("%d", &n);
    ll diag1min = oo, diag1max = -oo;
    ll diag2min = oo, diag2max = -oo;
    for (int i = 0; i < n; ++i) {
        ll x, y;
        scanf("%lld%lld", &x, &y);
        ll diag1 = x-y, diag2 = x+y;
        diag1min = min(diag1min, diag1);
        diag1max = max(diag1max, diag1);
        diag2min = min(diag2min, diag2);
        diag2max = max(diag2max, diag2);
    }
    if (n == 1)
        printf("%d\n", 4);
    else 
        printf("%lld\n",
               max(1LL, diag1max-diag1min) + max(1LL, diag2max-diag2min) + 4);
    return 0;
}