#include <bits/stdc++.h>
#define ll long long
using namespace std;
const int NMAX = 1e5;
const int INF = 2e9;
const ll INFLL = 1e18;
int k, n, ind;
ll left_sum, right_sum, answer, answer_c;
pair<int, int> v[NMAX + 1];
multiset<int> left_s, right_s;
ll pref_cost[NMAX + 5], suf_cost[NMAX + 1];
bool cmp(const pair<int, int>& a, const pair<int, int>& b) {
return a.first + a.second < b.first + b.second;
}
void insert_s(int x) {
int median = (left_s.empty() ? INF : *prev(left_s.end()));
if(x <= median) {
left_s.insert(x);
left_sum += x;
if((int) left_s.size() - (int) right_s.size() > 1) {
right_s.insert(*prev(left_s.end()));
right_sum += *prev(left_s.end());
left_sum -= *prev(left_s.end());
left_s.erase(prev(left_s.end()));
}
}
else {
right_s.insert(x);
right_sum += x;
if((int) right_s.size() - (int) left_s.size() > 0) {
left_s.insert(*right_s.begin());
left_sum += *right_s.begin();
right_sum -= *right_s.begin();
right_s.erase(right_s.begin());
}
}
}
void clear_s() {
left_s.clear();
right_s.clear();
left_sum = right_sum = 0;
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
cin >> k >> n;
for(int i = 1; i <= n; i++) {
char p, q;
int a, b;
cin >> p >> a >> q >> b;
if(a > b) {
swap(a, b);
}
if(p == q) {
answer_c += b - a;
}
else {
v[++ind] = {a, b};
}
}
answer_c += ind;
sort(v + 1, v + ind + 1, cmp);
for(int i = 1; i <= ind; i++) {
insert_s(v[i].first);
insert_s(v[i].second);
pref_cost[i] = right_sum - left_sum;
}
clear_s();
for(int i = ind; i >= 1; i--) {
insert_s(v[i].first);
insert_s(v[i].second);
suf_cost[i] = right_sum - left_sum;
}
if(k == 1) {
answer = pref_cost[ind];
}
else {
answer = INFLL;
for(int i = 1; i < n; i++) {
answer = min(answer, pref_cost[i] + suf_cost[i + 1]);
}
}
cout << answer + answer_c << '\n';
return 0;
}
