#include <bits/stdc++.h>
using namespace std;
#define int long long
#define REP(i, l, r) for (int i=(l); i<(r); ++i)
#define RREP(i, r, l) for (int i=(r); i>(l); --i)
#define vi vector<int>
#define popcount __builtin_popcountll
const int INF = 1LL<<60;
const int MOD = 1000000007;
template<typename T> istream &operator>>(istream &is, vector<T> &vec){ for (auto &v : vec) is >> v; return is; }
template <typename A, typename B>
string to_string(pair<A, B> p) {
return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}
template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> t) {
return "(" + to_string(get<0>(t)) + ", " + to_string(get<1>(t)) + ", " + to_string(get<2>(t)) + ")";
}
template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> t) {
return "(" + to_string(get<0>(t)) + ", " + to_string(get<1>(t)) + ", " + to_string(get<2>(t)) + ", " + to_string(get<3>(t)) + ")";
}
template <typename A>
string to_string(vector<A> v) {
bool first = true;
string result = "[";
for (A i : v) {
if (!first) result += ", ";
first = false;
result += to_string(i);
}
return result + "]";
}
string bin_string(int x) {
const int d = 64;
string result(d, ' ');
RREP(i, d-1, -1) result[d-1-i] = '0'+((x&1LL<<i)!=0);
return result;
}
vector<int> getZ(string s) {
int n = s.size();
vector<int> z(n);
int x = 0, y = 0;
REP(i, 1, n) {
z[i] = max(0LL, min(z[i-x], y-i+1));
while (i+z[i] < n && s[z[i]] == s[i+z[i]]) {
x = i;
y = i+z[i];
++z[i];
}
}
return z;
}
int powa(int base, int exp) {
if (exp<=0) return 1;
if (base<=0) return 0;
int val = powa(base, exp>>1);
val = val*val % MOD;
if (exp&1) {
val = val*base % MOD;
}
return val;
}
int n, k, res=INF;
vector<vi> blocks;
int bc(int d, int x1, int x2) {
int firstb = x1/(2*d), lastb = x2/(2*d);
int b = d*(lastb-firstb+1);
firstb *= 2*d;
lastb *= 2*d;
b -= min(d, x1-firstb);
b -= max(0LL, lastb+d-1-x2);
return b;
}
void getcost(int d) {
int bsq = ((n/d)*(n/d)+1)/2;
int wsq = (n/d)*(n/d)/2;
int mincost = (wsq-k) * d*d;
if (mincost >= res) return;
int cost = bsq * d*d;
for (vi block : blocks) {
int x1=block[0],y1=block[1],x2=block[2],y2=block[3];
--x1; --x2; --y1; --y2;
int h = bc(d, x1, x2);
int v = bc(d, y1, y2);
int b = h*v + (x2-x1+1-h)*(y2-y1+1-v);
int w = (x2-x1+1)*(y2-y1+1)-b;
cost -= b;
cost += w;
}
res = min(res, cost);
res = min(res, n*n-cost);
// cout << d << ": " << cost << ' ' << n*n-cost << '\n';
}
main() {
ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
cin >> n >> k;
blocks.assign(k, vi(4));
cin >> blocks;
vi factors;
for (int d=1; d*d<=n; ++d) {
if (n%d==0) {
factors.push_back(d);
if (d*d!=n && d != 1) factors.push_back(n/d);
}
}
sort(factors.rbegin(), factors.rend());
for (int d : factors) {
getcost(d);
}
cout << res;
}
