#include <bits/stdc++.h>

using namespace std;
#define int long long

vector<int> s, t;

int check(int x) {
    int res = 0;
    for (int i = 0; i < (int) s.size(); i++) {
        if (x < t[i]) res += s[i] + t[i] - 2 * x + 1;
        else if (x > s[i]) res += 2 * x - s[i] - t[i] + 1;
        else res += s[i] - t[i] + 1;
    }
    return res;
}

int add = 0;

int solve_for_one() {
    int res = (int) 1e18, n = (int) s.size();
    if (n == 0) return add;
    vector<int> all;
    for (int i = 0; i < n; i++) all.emplace_back(s[i]), all.emplace_back(t[i]);
    sort(all.begin(), all.end());
    for(int x : all) res = min(res, check(x));
//    if (check(all[n]) < res) res = check(all[n]);
//    if (check(all[n - 1]) < res) res = check(all[n - 1]);
    return res + add;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr), cout.tie(nullptr);
    int k, n, res = (int) 1e18;
    cin >> k >> n;
    for (int i = 0; i < n; i++) {
        int S, T;
        char P, Q;
        cin >> P >> S >> Q >> T;
        if (S < T) swap(S, T);
        if (P == Q) add += S - T;
        else s.emplace_back(S), t.emplace_back(T);
    }
    n = (int) s.size();
    if (n == 0) {
        cout << add;
        return 0;
    }
    if (k == 1) {
        cout << solve_for_one();
        return 0;
    }
    set<int> points;
    for (int i = 0; i < n; i++) points.insert(s[i]), points.insert(t[i]);
    for (int x: points) {
        vector<int> ss = s, tt = t;
        s.clear(), t.clear();
        int cur_res = 0;
        for (int i = 0; i < (int) ss.size(); i++) {
            if (tt[i] > x) s.emplace_back(ss[i]), t.emplace_back(tt[i]);
            else {
                if (x < tt[i]) cur_res += ss[i] + tt[i] - 2 * x + 1;
                else if (x > ss[i]) cur_res += 2 * x - ss[i] - tt[i] + 1;
                else cur_res += ss[i] - tt[i] + 1;
            }
        }
        cur_res += solve_for_one();
        s = ss, t = tt;
        res = min(res, cur_res);
    }
    cout << res;
    return 0;
}