//Copyright © 2022 Youngmin Park. All rights reserved.
//#pragma GCC optimize("O3")
//#pragma GCC target("avx2")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using vi = vector<int>;
using pii = pair<int, int>;
using vpi = vector<pii>;
using pll = pair<ll, ll>;
using vl = vector<ll>;
using vpl = vector<pll>;
using ld = long double;
template <typename T, size_t SZ>
using ar = array<T, SZ>;
#define all(v) (v).begin(), (v).end()
#define pb push_back
#define sz(x) (int)(x).size()
#define fi first
#define se second
#define lb lower_bound
#define ub upper_bound
#define FOR(i, a, b) for (int i = (a); i < (b); ++i)
#define F0R(i, a) FOR(i, 0, a)
#define ROF(i, a, b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i, a) ROF(i, 0, a)
#define REP(a) F0R(_, a)
const int INF = 1e9;
const ll LINF = 1e18;
const int MOD = 1e9 + 7; //998244353;
const ld PI = acos((ld)-1.0);
const int dx[4] = {1, 0, -1, 0}, dy[4] = {0, 1, 0, -1};
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
template <typename T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
template <typename T>
bool ckmin(T &a, const T &b) { return b < a ? a = b, 1 : 0; }
template <typename T>
bool ckmax(T &a, const T &b) { return b > a ? a = b, 1 : 0; }
template <typename A, typename B>
ostream &operator<<(ostream &os, const pair<A, B> &p)
{
return os << '(' << p.first << ", " << p.second << ')';
}
template <typename T_container, typename T = typename enable_if<!is_same<T_container, string>::value, typename T_container::value_type>::type>
ostream &operator<<(ostream &os, const T_container &v)
{
os << '{';
string sep;
for (const T &x : v)
os << sep << x, sep = ", ";
return os << '}';
}
void dbg_out()
{
cerr << endl;
}
template <typename Head, typename... Tail>
void dbg_out(Head H, Tail... T)
{
cerr << ' ' << H;
dbg_out(T...);
}
#ifdef LOCAL
#define dbg(...) cerr << "(" << #__VA_ARGS__ << "):", dbg_out(__VA_ARGS__)
#else
#define dbg(...) 42
#endif
inline namespace RecursiveLambda{
template <typename Fun>
struct y_combinator_result{
Fun fun_;
template <typename T>
explicit y_combinator_result(T &&fun): fun_(forward<T>(fun)){}
template <typename...Args>
decltype(auto) operator()(Args &&...args){
return fun_(ref(*this), forward<Args>(args)...);
}
};
template <typename Fun>
decltype(auto) y_combinator(Fun &&fun){
return y_combinator_result<decay_t<Fun>>(forward<Fun>(fun));
}
};
void setIO(string s) // USACO
{
#ifndef LOCAL
freopen((s + ".in").c_str(), "r", stdin);
freopen((s + ".out").c_str(), "w", stdout);
#endif
}
struct TrackMedian{
multiset<int> low, high;
ll sumLow{}, sumHigh{};
void add(int x) {
if (sz(low) == 0) {
sumLow += x;
low.insert(x);
return;
}
if (x > *low.rbegin()) {
high.insert(x);
sumHigh += x;
if (sz(high) > sz(low)) {
sumHigh -= *high.begin();
sumLow += *high.begin();
low.insert(*high.begin()), high.erase(high.begin());
}
}else{
low.insert(x);
sumLow += x;
if (sz(high) + 1 < sz(low)) {
sumHigh += *low.rbegin();
sumLow -= *low.rbegin();
high.insert(*low.rbegin());
low.erase(--low.end());
}
}
}
void remove(int x) {
if (x > *low.rbegin()) {
high.erase(high.find(x));
sumHigh -= x;
if (sz(high) + 1 < sz(low)) {
sumHigh += *low.rbegin();
sumLow -= *low.rbegin();
high.insert(*low.rbegin());
low.erase(--low.end());
}
}else{
low.erase(low.find(x));
sumLow -= x;
if (sz(high) > sz(low)) {
sumHigh -= *high.begin();
sumLow += *high.begin();
low.insert(*high.begin()), high.erase(high.begin());
}
}
}
ll calc() {
if (!sz(low)) return 0LL;
int med = *low.rbegin();
return sumHigh - 1LL * med * sz(high) + 1LL * med * sz(low) - sumLow;
}
};
void solve()
{
int k, n;
cin >> k >> n;
ll ans{};
ll extra = LINF;
vi order;
vpi a;
F0R(i, n) {
char c, d;
int l, r;
cin >> c >> l >> d >> r;
if (c != d) order.pb(l), order.pb(r), a.pb({l, r}), ans++;
else ans += abs(r - l);
}
if (k == 1) {
sort(all(order));
if (sz(order)) {
int med = order[sz(order) / 2];
for (auto &[l, r] : a) ans += abs(l - med) + abs(r - med);
}
cout << ans;
}else{
sort(all(a), [&](pii p, pii q) {
return (p.fi + p.se) < (q.fi + q.se);
});
TrackMedian lo, hi;
for (auto &[l, r] : a) hi.add(l), hi.add(r);
ckmin(extra, hi.calc());
F0R(i, sz(a)) {
hi.remove(a[i].fi), hi.remove(a[i].se);
lo.add(a[i].fi), lo.add(a[i].se);
while (i + 1 < sz(a) && (a[i + 1].fi + a[i + 1].se) == a[i].fi + a[i].se) {
i++;
hi.remove(a[i].fi), hi.remove(a[i].se);
lo.add(a[i].fi), lo.add(a[i].se);
}
ckmin(extra, hi.calc() + lo.calc());
}
cout << ans + extra;
}
}
int main()
{
cin.tie(0)->sync_with_stdio(0);
cin.exceptions(cin.failbit);
int testcase=1;
// cin >> testcase;
while (testcase--)
{
solve();
}
}
