#include <iostream>
#include <complex>
#include <vector>
#include <string>
#include <algorithm>
#include <cstdio>
#include <numeric>
#include <cstring>
#include <ctime>
#include <cstdlib>
#include <set>
#include <map>
#include <unordered_map>
#include <unordered_set>
#include <list>
#include <cmath>
#include <bitset>
#include <cassert>
#include <queue>
#include <stack>
#include <deque>
#include <random>
using namespace std;
template<typename T1, typename T2> inline void chkmin(T1 &a, T2 b) {if (a > b) a = b;}
template<typename T1, typename T2> inline void chkmax(T1 &a, T2 b) {if (a < b) a = b;}
#define files(FILENAME) read(FILENAME); write(FILENAME)
#define read(FILENAME) freopen((FILENAME + ".in").c_str(), "r", stdin)
#define write(FILENAME) freopen((FILENAME + ".out").c_str(), "w", stdout)
#define all(c) (c).begin(), (c).end()
#define sz(c) (int)(c).size()
#define left left228
#define right right228
#define y1 y1228
#define mp make_pair
#define pb push_back
#define y2 y2228
#define rank rank228
using ll = long long;
using ld = long double;
const string FILENAME = "input";
int main() {
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
//read(FILENAME);
int k, n;
cin >> k >> n;
ll add = 0;
vector<pair<int, int>> v;
vector<int> points;
int cnt = 0;
for (int i = 1; i <= n; i++) {
char p, q;
int s, t;
cin >> p >> s >> q >> t;
if (p == q) {
add += abs(s - t);
} else {
points.pb(s);
points.pb(t);
v.pb(mp(s, t));
cnt++;
}
}
if (k == 1) {
sort(all(points));
auto f = [&](int bridge) {
ll res = 0;
for (auto i: points) {
res += abs(i - bridge);
}
res += cnt;
return res;
};
int med = (sz(points) + 1) / 2;
cout << f(points[med - 1]) + add << '\n';
} else {
sort(all(v), [&](pair<int, int> a, pair<int, int> b) {
return a.first + a.second < b.first + b.second;
});
priority_queue<int> pql;
priority_queue<int, vector<int>, greater<int>> pqr;
ll lsum = 0, rsum = 0;
auto insert = [&](int x) {
int med = (pql.size() ? pql.top() : 1e9 + 10);
if (x <= med) {
pql.push(x);
lsum += x;
} else {
pqr.push(x);
rsum += x;
}
if (pqr.size() + 1 < pql.size()) {
int nxt = pql.top();
pql.pop();
pqr.push(nxt);
lsum -= nxt;
rsum += nxt;
} else if (pql.size() < pqr.size()) {
int nxt = pqr.top();
pqr.pop();
pql.push(nxt);
rsum -= nxt;
lsum += nxt;
}
};
vector<int> pref(sz(v) + 1);
for (int i = 1; i <= sz(v); i++) {
insert(v[i - 1].first);
insert(v[i - 1].second);
pref[i] = rsum - lsum;
}
while (!pql.empty()) {
pql.pop();
}
while (!pqr.empty()) {
pqr.pop();
}
lsum = 0;
rsum = 0;
ll ans = pref[sz(v)];
for (int i = sz(v); i >= 1; i--) {
insert(v[i - 1].first);
insert(v[i - 1].second);
chkmin(ans, rsum - lsum + pref[i - 1]);
}
cout << ans + add + cnt << '\n';
}
return 0;
}
