#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const int MAXN = 1e5 + 5;
int n, k;
ll lsum = 0, rsum = 0, pref[MAXN];
priority_queue <int> lpq;
priority_queue <int, vector <int>, greater <int>> rpq;
void insert(int x) {
int median = (lpq.size() ? lpq.top() : 1000000001);
if(x <= median) {
lpq.push(x);
lsum += x;
} else {
rpq.push(x);
rsum += x;
}
if(rpq.size() + 1 < lpq.size()) {
int nxt = lpq.top();
lpq.pop();
rpq.push(nxt);
lsum -= nxt, rsum += nxt;
} else if(lpq.size() < rpq.size()) {
int nxt = rpq.top();
rpq.pop();
lpq.push(nxt);
rsum -= nxt, lsum += nxt;
}
}
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
ll ss = 0, ans = 0;
cin >> k >> n;
vector <pair <int, int>> v = {{0, 0}};
for(int i = 0; i < n; i++) {
char a, b;
int x, y;
cin >> a >> x >> b >> y;
if(a == b) ss += abs(x - y);
else v.push_back({x, y});
}
sort(v.begin(), v.end(), [&](pair <int, int> p, pair <int, int> q) {
return p.first + p.second < q.first + q.second;
});
n = (int)v.size(); ss += n - 1;
for(int i = 1; i < n; i++) {
insert(v[i].first);
insert(v[i].second);
pref[i] = rsum - lsum;
}
ans = pref[n - 1];
if(k == 2) {
while(lpq.size()) lpq.pop();
while(rpq.size()) rpq.pop();
lsum = rsum = 0;
for(int i = n - 1; i > 0; i--) {
insert(v[i].first);
insert(v[i].second);
ans = min(ans, rsum - lsum + pref[i - 1]);
}
}
cout << ss + ans << "\n";
return 0;
}
