#include <bits/stdc++.h>
using namespace std;
using ll = long long;
int main() {
int k, n;
cin >> k >> n;
ll ans = 0;
vector<ll> vi;
vector<pair<int, int>> vpii;
for (int i = 0; i < n; i++) {
char a, b;
int x, y;
cin >> a >> x >> b >> y;
if (a == b) {
ans += abs(y - x);
} else {
vpii.push_back(minmax(x, y));
ans++;
}
}
sort(vpii.begin(), vpii.end(), [&](pair<int, int> a, pair<int, int> b) {
return (a.first + a.second) < (b.first + b.second);
});
// cout << "VPII:\n";
// for (auto a : vpii)
// cout << a.first << " " << a.second << "\n";
// cout << "\n";
vector<ll> pref(vpii.size() + 1), suf(vpii.size() + 1);
pref[0] = 0;
priority_queue<int> pqi;
priority_queue<int, vector<int>, greater<int>> pqi2;
ll sm = 0, sm2 = 0;
auto ins = [&](int x) {
if (pqi.empty() || x > pqi.top()) {
pqi2.push(x);
sm2 += x;
if (pqi2.size() > pqi.size()) {
sm2 -= pqi2.top();
sm += pqi2.top();
pqi.push(pqi2.top());
pqi2.pop();
}
} else {
pqi.push(x);
sm += x;
if (pqi.size() > pqi2.size() + 1) {
sm2 += pqi.top();
sm -= pqi.top();
pqi2.push(pqi.top());
pqi.pop();
}
}
};
for (int i = 1; i <= vpii.size(); i++) {
// cout << i << "\n";
ins(vpii[i - 1].first), ins(vpii[i - 1].second);
// cout << "PASS\n";
ll x = pqi.top();
pref[i] = (x * pqi.size() - sm) + (sm2 - x * pqi2.size());
}
// for (auto a : pref)
// cout << a << " ";
// cout << "\n";
if (k == 1) {
cout << ans + pref.back() << "\n";
return 0;
}
pqi = priority_queue<int>();
pqi2 = priority_queue<int, vector<int>, greater<int>>();
suf[vpii.size()] = 0;
sm = sm2 = 0;
for (int i = ((int)(vpii.size())) - 1; i >= 0; i--) {
ins(vpii[i].first), ins(vpii[i].second);
ll x = pqi.top();
suf[i] = (x * pqi.size() - sm) + (sm2 - x * pqi2.size());
}
//
// for (auto a : suf)
// cout << a << " ";
// cout << "\n";
ll minans = LLONG_MAX;
for (int i = 0; i <= vpii.size(); i++) {
minans = min(minans, ans + suf[i] + pref[i]);
}
cout << minans << "\n";
}
