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

template <typename T>
void compress(vector<T> &a) {
    auto sorted{a};
    sort(sorted.begin(), sorted.end());
    sorted.erase(unique(sorted.begin(), sorted.end()), sorted.end());
    for (auto &&x : a) {
        x = lower_bound(sorted.begin(), sorted.end(), x) - sorted.begin();
    }
}

int main() {
    int64_t n, m;
    cin >> n >> m;
    vector<int64_t> l(m), r(m);
    for (int i = 0; i < m; i++) {
        int64_t x, y;
        cin >> x >> y;
        l.at(i) = x + y;
        r.at(i) = x - y;
    }
    sort(l.begin(), l.end());
    l.erase(unique(l.begin(), l.end()), l.end());
    sort(r.begin(), r.end());
    r.erase(unique(r.begin(), r.end()), r.end());
    int64_t ans = 0;
    for (auto &&x : l) {
        ans += min(x - 1, 2 * n + 1 - x);
    }
    for (auto &&x : r) {
        ans += min(x + n, n - x);
    }

    vector<int64_t> merged0, merged1;
    int l0 = 0, l1 = 0;
    for (auto &&x : l) {
        if (x % 2 == 0) {
            merged0.emplace_back(x);
            l0++;
        } else {
            merged1.emplace_back(x);
            l1++;
        }
    }
    for (auto &&x : r) {
        if (x % 2 == 0) {
            merged0.emplace_back(2 + abs(x));
            merged0.emplace_back(2 * n - abs(x) + 1);
        } else {
            merged1.emplace_back(2 + abs(x));
            merged1.emplace_back(2 * n - abs(x) + 1);
        }
    }
    compress(merged0);
    compress(merged1);

    vector<int64_t> s0(300001), s1(300001);
    for (int i = 0; i < l0; i++) {
        s0.at(merged0.at(i) + 1)++;
    }
    for (int i = 0; i < l1; i++) {
        s1.at(merged1.at(i) + 1)++;
    }
    for (int i = 0; i < 300000; i++) {
        s0.at(i + 1) += s0.at(i);
        s1.at(i + 1) += s1.at(i);
    }

    int r0 = (merged0.size() - l0) / 2;
    int r1 = (merged1.size() - l1) / 2;
    for (int i = 0; i < r0; i++) {
        int a = merged0.at(l0 + 2 * i);
        int b = merged0.at(l0 + 2 * i + 1);
        ans += s0.at(a) - s0.at(b);
    }
    for (int i = 0; i < r1; i++) {
        int a = merged1.at(l1 + 2 * i);
        int b = merged1.at(l1 + 2 * i + 1);
        ans += s1.at(a) - s1.at(b);
    }

    cout << ans << endl;
    return 0;
}