#include <bits/stdc++.h> using namespace std; typedef long long ll; const int maxn = 1e5 + 10; const ll inf = 1e18; vector<pair<int, int> > eve; ll solve(){ int n = eve.size(); vector<ll> a(2 * n + 1); for (int i = 0; i < n; i++){ a[2 * i + 0 + 1] = eve[i].first; a[2 * i + 1 + 1] = eve[i].second; } sort(a.begin() + 1, a.end()); n = 2 * n; for (int i = 1; i <= n; i++) a[i] += a[i - 1]; ll answer = inf; for (int i = 1; i <= n; i++){ ll T = a[i] - a[i - 1]; answer = min(answer, T * (i - (n - i)) - a[i] + (a[n] - a[i])); } return answer + eve.size(); } int main(){ ios_base::sync_with_stdio(false); int k, n; cin >> k >> n; ll answer = 0; for (int i = 0; i < n; i++){ int x, y; char a, b; cin >> a >> x >> b >> y; if (a == b){ answer += abs(x - y); continue; } if (a == 'B') swap(x, y); eve.push_back({x, y}); } if (k == 1){ cout << answer + solve() << '\n'; return 0; } }