#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 solve() {
ll K, N;
cin >> K >> N;
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];
});
priority_queue<ll> lpq;
priority_queue<ll, vector<ll>, greater<ll>> rpq;
ll totl = 0, totr = 0;
auto push = [&](ll x) -> void {
ll med = (lpq.empty() ? MAX : lpq.top());
if (x <= med) {
lpq.push(x);
totl += x;
}
else {
rpq.push(x);
totr += x;
}
while (lpq.size() - 1 > rpq.size()) {
ll h = lpq.top();
rpq.push(h);
lpq.pop();
totr += h;
totl -= h;
}
while (lpq.size() < rpq.size()) {
ll h = rpq.top();
lpq.push(h);
rpq.pop();
totl += h;
totr -= h;
}
};
vector<ll> pref(vec.size() + 1);
for (ll i = 0; i < vec.size(); ++i) {
push(vec[i][0]);
push(vec[i][1]);
pref[i + 1] = totr - totl;
}
ll ans = pref[vec.size()];
if (K == 2) {
while (!lpq.empty()) lpq.pop();
while (!rpq.empty()) rpq.pop();
totl = totr = 0;
for (ll i = ll(vec.size()) - 1; i >= 0; --i) {
push(vec[i][0]);
push(vec[i][1]);
ans = min(ans, pref[i] + totr - totl);
}
}
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;
}
