#include <bits/stdc++.h>
#define nl '\n'
#ifdef LOCAL
#include "template/debug.hpp"
#else
#define dbg(...) ;
#define timer(...) ;
#endif
struct MedianSolver {
std::multiset<int> pql, pqr;
int64_t suml = 0, sumr = 0;
void balance() {
while (pql.size() > pqr.size()) {
int to_move = *pql.rbegin();
pqr.insert(to_move);
pql.erase(--pql.end());
suml -= to_move;
sumr += to_move;
}
while (pqr.size() > pql.size() + 1) {
int to_move = *pqr.begin();
pql.insert(to_move);
pqr.erase(pqr.begin());
suml += to_move;
sumr -= to_move;
}
}
void add_value(int x) {
if (pqr.empty() || x >= *pqr.begin()) {
sumr += x;
pqr.insert(x);
} else {
suml += x;
pql.insert(x);
}
balance();
}
void rem_value(int x) {
if (x >= *pqr.begin()) {
sumr -= x;
pqr.erase(pqr.find(x));
} else {
suml -= x;
pql.erase(pql.find(x));
}
balance();
}
int get_median() {
return *pqr.begin();
}
int64_t get_solution() {
if (pqr.empty()) return 0;
int64_t med = get_median();
return med * pql.size() - suml + sumr - med * pqr.size();
}
};
signed main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int theta, n;
std::cin >> theta >> n;
if (theta == 1) {
std::vector<int> x_vals;
int64_t ans = 0;
for (int i = 0; i < n; i++) {
char p, q;
int s, t;
std::cin >> p >> s >> q >> t;
if (p == q) {
ans += std::abs(t - s);
} else {
x_vals.push_back(s);
x_vals.push_back(t);
ans++;
}
}
std::sort(x_vals.begin(), x_vals.end());
int med = x_vals.size() / 2;
for (int i = 0; i < (int)x_vals.size(); i++) {
ans += std::abs(x_vals[i] - x_vals[med]);
}
std::cout << ans << nl;
return 0;
}
std::vector<int> xs;
std::vector<std::pair<int, int>> peoples;
int64_t obvious = 0;
for (int i = 0; i < n; i++) {
char p, q;
int s, t;
std::cin >> p >> s >> q >> t;
if (p == q) {
obvious += std::abs(t - s);
} else {
if (s > t) std::swap(s, t);
xs.push_back(s);
xs.push_back(t);
peoples.emplace_back(s, t);
}
}
n = peoples.size();
if (n == 0) {
std::cout << obvious << nl;
return 0;
}
if (n == 1) {
std::cout << peoples.front().second - peoples.front().first + 1 + obvious << nl;
return 0;
}
MedianSolver solverl, solverr;
for (int i = 0; i < n; i++) {
solverr.add_value(peoples[i].first);
solverr.add_value(peoples[i].second);
}
std::sort(peoples.begin(), peoples.end(), [&](auto& a, auto& b) {
return a.first + a.second < b.first + b.second;
});
int64_t ans = solverl.get_solution() + solverr.get_solution();
for (int i = 0; i < n; i++) {
solverr.rem_value(peoples[i].first);
solverr.rem_value(peoples[i].second);
solverl.add_value(peoples[i].first);
solverl.add_value(peoples[i].second);
ans = std::min(ans, solverl.get_solution() + solverr.get_solution());
}
std::cout << ans + n + obvious << nl;
}
/*
1 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
2 5
B 0 A 4
B 1 B 3
A 5 B 7
B 2 A 6
B 1 A 7
*/
