#include <bits/stdc++.h>
#define DEBUG 0
using namespace std;
const int MAX_N = 1e5 + 10;
const int INF = 1e9 + 7;
long long pre[MAX_N];
long long suml, sumr;
priority_queue <int> pql;
priority_queue <int, vector <int>, greater <int>> pqr;
void add(const int &v) {
int median = INF;
if(!pql.empty()) {
median = pql.top();
}
if(v <= median) {
suml += v;
pql.push(v);
}
else {
sumr += v;
pqr.push(v);
}
if(pql.size() > pqr.size() + 1) {
pqr.push(pql.top());
sumr += pql.top();
suml -= pql.top();
pql.pop();
}
else if(pql.size() < pqr.size()) {
pql.push(pqr.top());
sumr -= pqr.top();
suml += pqr.top();
pqr.pop();
}
}
int main() {
cin.tie(nullptr)->sync_with_stdio(false);
int K, N;
cin >> K >> N;
vector <pair <int, int>> vec({make_pair(-INF, -INF)});
long long same_side = 0;
for(int i = 1; i <= N; i++) {
char p, q;
int s, t;
cin >> p >> s >> q >> t;
if(p == q) {
same_side += abs(s - t);
}
else {
vec.emplace_back(s, t);
}
}
sort(vec.begin(), vec.end(), [&](const pair <int, int> &a, const pair <int, int> &b) {
return a.first + a.second < b.first + b.second;
});
N = vec.size() - 1;
same_side += N;
for(int i = 1; i <= N; i++) {
add(vec[i].first), add(vec[i].second);
pre[i] = sumr - suml;
}
long long ans = pre[N];
if(K == 2) {
while(!pql.empty()) {
pql.pop();
}
while(!pqr.empty()) {
pqr.pop();
}
suml = sumr = 0;
for(int i = N; i >= 1; i--) {
add(vec[i].first), add(vec[i].second);
ans = min(ans, pre[i - 1] + sumr - suml);
}
}
cout << ans + same_side;
return 0;
}
