#include <bits/stdc++.h>
#define ll long long
using namespace std;
ll ltot, rtot;
priority_queue<int> pql;
priority_queue<int, vector<int>, greater<int>> pqr;
void put(ll x) {
ll med = pql.empty() ? LLONG_MAX : pql.top(), tmp;
if (x <= med) {
pql.push(x);
ltot += x;
} else {
pqr.push(x);
rtot += x;
}
if (pqr.size() + 1 < pql.size()) {
tmp = pql.top();
pql.pop();
pqr.push(tmp);
ltot -= tmp;
rtot += tmp;
} else if (pqr.size() > pql.size()) {
tmp = pqr.top();
pqr.pop();
pql.push(tmp);
ltot += tmp;
rtot -= tmp;
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
int k, n, i;
cin >> k >> n;
char az, bz;
ll ap, bp, ss = 0, best = 0;
vector<ll> pos;
vector<pair<ll, ll>> ppl;
for (i = 0; i < n; i++) {
cin >> az >> ap >> bz >> bp;
if (az == bz) ss += abs(ap - bp);
else {
if (ap > bp) swap(ap, bp);
ppl.push_back({ap, bp});
ss++;
}
}
n = ppl.size();
sort(ppl.begin(), ppl.end(), [](const pair<int, int>& one, const pair<int, int>& two){return one.first + one.second < two.first + two.second;});
ltot = rtot = 0;
vector<ll> pref(n + 1);
for (i = 0; i < n; i++) {
put(ppl[i].first);
put(ppl[i].second);
pref[i + 1] = rtot - ltot;
}
best = pref[n];
if (k == 2) {
while (not pql.empty()) pql.pop();
while (not pqr.empty()) pqr.pop();
ltot = rtot = 0;
for (i = n - 1; i >= 0; i--) {
put(ppl[i].first);
put(ppl[i].second);
best = min(best, rtot - ltot + pref[i]);
}
}
cout << ss + best;
return 0;
}
