# include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
# define f first
# define s second
using namespace std;
const int N = 1e5 + 2;
struct st{
int cnt, l, r;
long long sum = 0;
st(){
cnt = sum = l = r = 0;
}
}t[N * 30];
int n, k, cn, sz = 1, root[N];
long long ans = 1e18, p1[N], s1[N], p2[N], s2[N], ss;
vector <int> v, v1, v2;
pair < pair <int, int> , pair <char, char> > a[N];
pair <int, pair <int, int> > b[N];
void update(int ov, int nv, int pos, int tl = 0, int tr = 1e9){
if(tl == tr){
t[nv].cnt = t[ov].cnt + 1;
t[nv].sum = t[ov].sum + tl;
} else {
int tm = (tl + tr) >> 1;
if(pos <= tm){
if(!t[nv].l) t[nv].l = ++ sz;
t[nv].r = t[ov].r;
update(t[ov].l, t[nv].l, pos, tl, tm);
} else {
if(!t[nv].r) t[nv].r = ++ sz;
t[nv].l = t[ov].l;
update(t[ov].r, t[nv].r, pos, tm + 1, tr);
}
t[nv].sum = t[ t[nv].l ].sum + t[ t[nv].r ].sum;
t[nv].cnt = t[ t[nv].l ].cnt + t[ t[nv].r ].cnt;
}
}
pair <long long, int> get(int ov, int nv, int l, int r, int tl = 0, int tr = 1e9){
if(t[nv].cnt - t[ov].cnt <= 0) return {0, 0};
if(l <= tl && tr <= r) return {t[nv].sum - t[ov].sum, t[nv].cnt - t[ov].cnt};
int tm = (tl + tr) >> 1;
pair <long long, int> res, cp;
if(l <= tm) res = get(t[ov].l, t[nv].l, l, r, tl, tm);
if(tm < r){
cp = get(t[ov].r, t[nv].r, l, r, tm + 1, tr);
res.f += cp.f;
res.s += cp.s;
}
return res;
}
int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> k >> n;
for(int i = 1; i <= n; i ++){
cin >> a[i].s.f >> a[i].f.f >> a[i].s.s >> a[i].f.s;
if(a[i].f.f > a[i].f.s) swap(a[i].f.f, a[i].f.s);
if(a[i].s.f != a[i].s.s) {
cn ++;
v1.push_back(a[i].f.f), v2.push_back(a[i].f.s);
b[cn] = {(a[i].f.f + a[i].f.s + 1), {a[i].f.f, a[i].f.s}};
} else {
ss += abs(a[i].f.s - a[i].f.f);
}
v.push_back(a[i].f.f);
v.push_back(a[i].f.s);
}
v1.push_back(-1e9);
v2.push_back(-1e9);
sort(b + 1, b + cn + 1);
sort(v.begin(), v.end());
v.resize(unique(v.begin(), v.end()) - v.begin());
sort(v1.begin(), v1.end());
sort(v2.begin(), v2.end());
for(int i = 1; i <= cn; i ++){
p1[i] = p1[i - 1] + v1[i];
p2[i] = p2[i - 1] + v2[i];
}
for(int i = cn; i >= 1; i --){
s1[i] = s1[i + 1] + v1[i];
s2[i] = s2[i + 1] + v2[i];
}
int pos = 0, ps = 0;
for(int i = 0; i < v.size(); i ++){
long long res = 0;
int x = v[i];
while(pos + 1 <= cn && v1[pos + 1] <= x) pos ++;
while(ps + 1 <= cn && v2[ps + 1] <= x) ps ++;
res += x * 1ll * pos - p1[pos];
res += x * 1ll * ps - p2[ps];
res += s1[pos + 1] - x * 1ll * (cn - pos);
res += s2[ps + 1] - x * 1ll * (cn - ps);
ans = min(ans, res + cn + ss);
}
if(k == 2){
if(n > 1000) assert(0);
long long mn = 1e18;
for(int i = 1; i <= cn; i ++){
root[i * 2 - 1] = ++ sz;
update(root[i * 2 - 2], root[i * 2 - 1], b[i].s.f);
root[i * 2] = ++ sz;
update(root[i * 2 - 1], root[i * 2], b[i].s.s);
}
for(int i = 0; i < v.size(); i ++){
ps = 0;
for(int j = i + 1; j < v.size(); j ++){
long long res = 0;
int x = (v[i] + v[j] + 1);
while(b[ps + 1].f <= x && ps + 1 <= cn) ps ++;
pair <long long, int> p = get(root[0], root[ps * 2], 0, v[i]);
res += v[i] * 1ll * p.s - p.f;
p = get(root[0], root[ps * 2], v[i] + 1, 1e9);
res += p.f - v[i] * 1ll * p.s;
p = get(root[ps * 2], root[cn * 2], 0, v[j]);
res += v[j] * 1ll * p.s - p.f;
p = get(root[ps * 2], root[cn * 2], v[j] + 1, 1e9);
res += p.f - v[j] * 1ll * p.s;
if(mn > res) mn = res;
}
}
ans = min(ans, mn + cn + ss);
}
cout << ans;
// cin.get(); cin.get();
}
/***
2 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
***/
