#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <iomanip>
#include <set>
#include <map>
#include <numeric>
#include <iomanip>
#include <unordered_set>
#include <unordered_map>
#include <bitset>
#include <queue>
#include <deque>
#include <stack>
#include <cmath>
#include <tuple>
#include <cassert>
#include <array>
#include <list>
#include <random>
#include <initializer_list>
using namespace std;
using ll = long long;
using u64 = unsigned long long;
using db = double;
using ld = long double;
constexpr ll INF = 1E18;
constexpr ll MIN = -INF;
constexpr ll MAX = INF;
constexpr ll N = 1E5;
void solve2(ll N) {
vector<ll> vec;
ll ans = 0;
for (ll i = 0; i < N; ++i) {
char P, Q;
ll s, t;
cin >> P >> s >> Q >> t;
if (P == Q) {
ans += abs(s - t);
}
else {
ans += 1;
vec.push_back(s);
vec.push_back(t);
}
}
sort(vec.begin(), vec.end());
if (!vec.empty()) {
ll Z = vec[(vec.size() - 1) / 2];
for (ll i = 0; i < vec.size(); ++i) {
ans += abs(vec[i] - Z);
}
}
cout << ans << '\n';
}
void solve() {
ll K, N;
cin >> K >> N;
if (K == 1) {
solve2(N);
return;
}
vector<array<ll, 2>> vec;
ll add = 0;
for (ll i = 0; i < N; ++i) {
char P, Q;
ll s, t;
cin >> P >> s >> Q >> t;
if (P == Q) {
add += abs(s - t);
}
else {
add += 1;
vec.push_back({ s, t });
}
}
sort(vec.begin(), vec.end(), [&](auto a, auto b) {
return a[0] + a[1] < b[0] + b[1];
});
set<ll> ls, rs;
ll med;
auto push = [&](ll x) -> void {
if (rs.empty() || x >= *rs.begin()) {
rs.insert(x);
}
else {
ls.insert(x);
}
while (ll(ls.size()) - 1 > ll(rs.size())) {
rs.insert(*--ls.end());
ls.erase(--ls.end());
}
while (ls.size() < rs.size()) {
ls.insert(*rs.begin());
rs.erase(rs.begin());
}
med = *--ls.end();
};
vector<ll> pref(vec.size() + 1), suf(vec.size() + 1);
for (ll i = 0; i < vec.size(); ++i) {
push(vec[i][0]);
push(vec[i][1]);
for (ll j = 0; j <= i; ++j) {
pref[i + 1] += abs(vec[j][0] - med);
pref[i + 1] += abs(vec[j][1] - med);
}
}
ls.clear();
rs.clear();
for (ll i = vec.size() - 1; i >= 0; --i) {
push(vec[i][0]);
push(vec[i][1]);
for (ll j = vec.size() - 1; j >= i; --j) {
suf[i] += abs(vec[j][0] - med);
suf[i] += abs(vec[j][1] - med);
}
}
ll ans = MAX;
for (ll i = 0; i <= vec.size(); ++i) {
ans = min(ans, pref[i] + suf[i]);
}
cout << ans + add << '\n';
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;
/*cin >> t;*/
while (t--) {
solve();
}
return 0;
}
