#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<ll> S, T, 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;
S.push_back(s);
T.push_back(t);
vec.push_back(s);
vec.push_back(t);
}
}
/*vector<ll> id(S.size());
iota(id.begin(), id.end(), 0LL);
sort(id.begin(), id.end(), [&](ll i, ll j) {
return S[i] + T[i] < S[j] + T[j];
});*/
priority_queue<ll> lq;
priority_queue<ll, vector<ll>, greater<ll>> rq;
sort(vec.begin(), vec.end());
ll Z = vec[(vec.size() - 1) / 2];
for (ll i = 0; i < vec.size(); ++i) {
ans += abs(vec[i] - Z);
}
cout << ans << '\n';
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;
/*cin >> t;*/
while (t--) {
solve();
}
return 0;
}
