#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;
}

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr), cout.tie(nullptr);
    int k, n, add = 0, 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) {
        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());
        if (check(all[n]) < res) res = check(all[n]);
        if (check(all[n + 1]) < res) res = check(all[n + 1]);
        cout << res + add;
        return 0;
    }
    return 0;
}