/*
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*/
#include <iostream>
#include <complex>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <numeric>
#include <cstring>
#include <ctime>
#include <cstdlib>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <cmath>
#include <bitset>
#include <cassert>
#include <queue>
#include <stack>
#include <iomanip>
#include <deque>
using namespace std;
template<typename T1, typename T2>inline void chkmin(T1 &x, T2 y) { if (x > y) x = y; }
template<typename T1, typename T2>inline void chkmax(T1 &x, T2 y) { if (x < y) x = y; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const pair<T, U> &_p) { _out << _p.first << ' ' << _p.second; return _out; }
template<typename T, typename U> inline istream &operator>> (istream &_in, pair<T, U> &_p) { _in >> _p.first >> _p.second; return _in; }
template<typename T> inline ostream &operator<< (ostream &_out, const vector<T> &_v) { if (_v.empty()) { return _out; } _out << _v.front(); for (auto _it = ++_v.begin(); _it != _v.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline istream &operator>> (istream &_in, vector<T> &_v) { for (auto &_i : _v) { _in >> _i; } return _in; }
template<typename T> inline ostream &operator<< (ostream &_out, const set<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const multiset<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const unordered_set<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T> inline ostream &operator<< (ostream &_out, const unordered_multiset<T> &_s) { if (_s.empty()) { return _out; } _out << *_s.begin(); for (auto _it = ++_s.begin(); _it != _s.end(); ++_it) { _out << ' ' << *_it; } return _out; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const map<T, U> &_m) { if (_m.empty()) { return _out; } _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')'; for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) { _out << ", (" << _it->first << ": " << _it->second << ')'; } return _out; }
template<typename T, typename U> inline ostream &operator<< (ostream &_out, const unordered_map<T, U> &_m) { if (_m.empty()) { return _out; } _out << '(' << _m.begin()->first << ": " << _m.begin()->second << ')'; for (auto _it = ++_m.begin(); _it != _m.end(); ++_it) { _out << ", (" << _it->first << ": " << _it->second << ')'; } return _out; }
#define sz(c) (int)(c).size()
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define left left228
#define right right228
#define next next228
#define rank rank228
#define prev prev228
#define y1 y1228
#define read(FILENAME) freopen((FILENAME + ".in").c_str(), "r", stdin)
#define write(FILENAME) freopen((FILENAME + ".out").c_str(), "w", stdout)
#define files(FILENAME) read(FILENAME), write(FILENAME)
#define pb push_back
#define x first
#define y second
const string FILENAME = "input";
const int MAXN = 100228;
//11:50
//16:50
int n, k;
int x1[MAXN], y1[MAXN], x2[MAXN], y2[MAXN];
long long ans = 1e18;
long long get(int t, int posx, int len, int yl, int yr, int x) {
long long res = 0;
int ly = yl / x;
int ry = yr / x;
if (ly == ry) {
if ((ly + posx) % 2 == t) {
res += 1LL * len * (yr - yl + 1);
} else {
res -= 1LL * len * (yr - yl + 1);
}
} else {
// exit(1);
if (yl % x != 0) {
if ((posx + ly) % 2 == t) {
res += 1LL * len * (x - yl % x);
} else {
res -= 1LL * len * (x - yl % x);
}
ly++;
}
if (yr % x != x - 1) {
if ((posx + ry) % 2 == t) {
res += 1LL * len * (yr % x + 1);
} else {
res -= 1LL * len * (yr % x + 1);
}
ry--;
}
if (ly <= ry) {
if ((posx + ly) % 2 == t) {
if ((ry - ly + 1) % 2) {
res += 1LL * len * x;
}
} else {
if ((ry - ly + 1) % 2) {
res -= 1LL * len * x;
}
}
}
}
return res;
}
long long check(int t, int x) {
long long res = 0;
if (t == 1) {
res += 1LL * (1LL * (n / x) * (n / x) + 1) / 2 * x * x;
} else {
res += 1LL * (1LL * (n / x) * (n / x) ) / 2 * x * x;
}
// cout << res << endl;
for (int i = 0; i < k; i++) {
int lx = x1[i] / x;
int rx = x2[i] / x;
int ly = y1[i] / x;
int ry = y2[i] / x;
if (lx == rx) {
res += get(t, lx, x2[i] - x1[i] + 1, y1[i], y2[i], x);
continue;
}
// exit(1);
if (x1[i] % x != 0) {
res += get(t, lx, x - x1[i] % x, y1[i], y2[i], x);
lx++;
}
if (x2[i] % x != x - 1) {
res += get(t, rx, x2[i] % x + 1, y1[i], y2[i], x);
rx--;
}
if (lx <= rx) {
if ((rx - lx + 1) % 2 == 1) {
res += get(t, lx, x, y1[i], y2[i], x);
}
}
}
return res;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
//read(FILENAME);
cin >> n >> k;
for (int i = 0; i < k; i++) {
cin >> x1[i] >> y1[i] >> x2[i] >> y2[i];
x1[i]--;
y1[i]--;
x2[i]--;
y2[i]--;
}
for (int i = 1; i < n; i++) {
if (n % i == 0) {
chkmin(ans, check(0, i));
chkmin(ans, check(1, i));
}
}
cout << ans << '\n';
}
