#include "bits/stdc++.h"
#ifdef LOCAL
#include "dbg.h"
#else
#define dbg(...) 0
#endif
#define fox(i, n) for (int i = 0; i < (n); ++i)
#define rep(i, a, b) for (int i = (a); i < (b); ++i)
#define rin(i, a, b) for (int i = (a); i <= (b); ++i)
#define rrep(i, a, b) for (int i = (a); i >= (b); --i)
#define fore(x, v) for (auto &&x : v)
#define forp(a, b, v) for (auto &&[a, b] : v)
#define pb push_back
#define eb emplace_back
#define F first
#define S second
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define EL "\n"
using namespace std;
using vi = vector<int>;
using ll = long long;
using vll = vector<ll>;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
using vpii = vector<pii>;
using vpll = vector<pll>;
template<class T> using pq = priority_queue<T>;
template<class T> using pqg = priority_queue<T, vector<T>, greater<>>;
template<class T>
int sz(T& container) {
return (int) container.size();
}
template<class T> bool ckmin(T& a, const T& b) {
return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) {
return a < b ? a = b, 1 : 0; }
ll cdiv(ll a, ll b) { return a/b+((a^b)>0&&a%b); }
ll fdiv(ll a, ll b) { return a/b-((a^b)<0&&a%b); }
//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//ll urand(int a, int b) { return rng() % (b-a+1) + a; }
//const vector<pii> deltas = {{1, 0}, {-1, 0}, {0, 1}, {0, -1}};
const int INF = 0x3f3f3f3f;
template<int MOD, int RT> struct mint {
static const int mod = MOD;
static constexpr mint rt() { return RT; } // primitive root for FFT
int v; explicit operator int() const { return v; } // explicit -> don't silently convert to int
mint():v(0) {}
mint(ll _v) { v = int((-MOD < _v && _v < MOD) ? _v : _v % MOD);
if (v < 0) v += MOD; }
bool operator==(const mint& o) const {
return v == o.v; }
friend bool operator!=(const mint& a, const mint& b) {
return !(a == b); }
friend bool operator<(const mint& a, const mint& b) {
return a.v < b.v; }
mint& operator+=(const mint& o) {
if ((v += o.v) >= MOD) v -= MOD;
return *this; }
mint& operator-=(const mint& o) {
if ((v -= o.v) < 0) v += MOD;
return *this; }
mint& operator*=(const mint& o) {
v = int((ll)v*o.v%MOD); return *this; }
mint& operator/=(const mint& o) { return (*this) *= inv(o); }
friend mint pow(mint a, ll p) {
mint ans = 1; assert(p >= 0);
for (; p; p /= 2, a *= a) if (p&1) ans *= a;
return ans; }
friend mint inv(const mint& a) { assert(a.v != 0);
return pow(a,MOD-2); }
mint operator-() const { return mint(-v); }
mint& operator++() { return *this += 1; }
mint& operator--() { return *this -= 1; }
friend mint operator+(mint a, const mint& b) { return a += b; }
friend mint operator-(mint a, const mint& b) { return a -= b; }
friend mint operator*(mint a, const mint& b) { return a *= b; }
friend mint operator/(mint a, const mint& b) { return a /= b; }
friend istream& operator>> (istream& is, mint& a) {
is >> a.v;
return is;
}
friend ostream& operator<< (ostream& os, const mint& a) {
os << a.v;
return os;
}
};
using mi = mint<int(1e9+7), 5>;
struct bridge {
pq<ll> left; // sz(left) >= sz(right)
pqg<ll> right;
ll cost{};
// median = left.top()
void adjust(bool l) {
ll old, dif;
if (l) {
if (sz(left) - sz(right) <= 1) return;
old = left.top(); left.pop();
dif = left.top() - old;
} else {
if (sz(left) >= sz(right)) return;
old = right.top(); right.pop();
dif = old - left.top();
cost -= dif;
}
cost += dif * sz(left);
cost -= dif * sz(right);
if (l) right.push(old);
else left.push(old);
}
void insert(ll p) {
if (left.empty()) {
left.push(p); return;
}
cost += abs(p - left.top());
if (p > left.top()) {
right.push(p);
adjust(false);
} else {
left.push(p);
adjust(true);
}
}
void insert(pll p) {
insert(p.F); insert(p.S);
}
};
void solve() {
int k, n; cin >> k >> n;
ll ans = 0;
vpll v;
fox(i, n) {
char a, b; int x, y; cin >> a >> x >> b >> y;
if (a == b) ans += abs(x-y);
else {
v.eb(minmax(x, y)); ++ans;
}
}
sort(all(v), [](pll a, pll b) {return a.F+a.S < b.F+b.S;});
n = sz(v);
vll lcost(n+1), rcost(n+1);
bridge l, r;
rin(i, 1, n) {
l.insert(v[i-1]);
r.insert(v[n-i]);
lcost[i] = l.cost;
rcost[i] = r.cost;
}
ll best;
if (k == 1) {
best = lcost[n];
} else {
best = 1e18;
rin(i, 0, n)
ckmin(best, lcost[i] + rcost[n-i]);
}
cout << best + ans << EL;
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
// int t;
// cin >> t;
// while (t--)
solve();
return 0;
}
